cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 19 results. Next

A099764 a(n) = n^2 * (n+1)^2 * (n+2)^2 = 36*A001249(n-1).

Original entry on oeis.org

0, 36, 576, 3600, 14400, 44100, 112896, 254016, 518400, 980100, 1742400, 2944656, 4769856, 7452900, 11289600, 16646400, 23970816, 33802596, 46785600, 63680400, 85377600, 112911876, 147476736, 190440000, 243360000, 308002500, 386358336
Offset: 0

Views

Author

Kari Lajunen (Kari.Lajunen(AT)Welho.com), Nov 11 2004

Keywords

Examples

			a(0) = 1^3 - 1^3 = 0;
a(1) = (1+3)^3 - (1^3+3^3) = 64 - 28 = 36;
a(2) = (1+3+5)^3 - (1^3+3^3+5^3) = 729 - 153 = 576;
a(3) = (1+3+5+7)^3 - (1^3+3^3+5^3+7^3) = 4096 - 496 = 3600;
a(4) = (1+3+5+7+9)^3 - (1^3+3^3+5^3+7^3+9^3) = 15625 - 1225 = 14400; etc. - _Philippe Deléham_, Mar 10 2014
		

References

  • Jolley, Summation of Series, Dover (1961).

Crossrefs

Programs

Formula

Sum_{n>=1} 1/a(n) = Pi^2/4-39/16 = 0.029901100272... [Jolley eq 241]
G.f.: 36*x*(1+x)*(1 +8*x +x^2)/(1-x)^7 . - R. J. Mathar, Oct 03 2011
a(n) = (Sum_{k=0..n} (2*k+1))^3 - Sum_{k=0..n} (2*k+1)^3. - Philippe Deléham, Mar 10 2014
a(n) = A001014(n+1) - A002593(n+1). - Philippe Deléham, Mar 10 2014
E.g.f.: exp(x)*x*(36+252*x+330*x^2+138*x^3+21*x^4+x^5). - Stefano Spezia, Sep 04 2019
Sum_{n>=1} (-1)^(n+1)/a(n) = Pi^2/24 - 7/16. - Amiram Eldar, Jul 02 2020

A008459 Square the entries of Pascal's triangle.

Original entry on oeis.org

1, 1, 1, 1, 4, 1, 1, 9, 9, 1, 1, 16, 36, 16, 1, 1, 25, 100, 100, 25, 1, 1, 36, 225, 400, 225, 36, 1, 1, 49, 441, 1225, 1225, 441, 49, 1, 1, 64, 784, 3136, 4900, 3136, 784, 64, 1, 1, 81, 1296, 7056, 15876, 15876, 7056, 1296, 81, 1, 1, 100, 2025, 14400, 44100, 63504, 44100, 14400, 2025, 100, 1
Offset: 0

Views

Author

Keywords

Comments

Number of lattice paths from (0, 0) to (n, n) with steps (1, 0) and (0, 1), having k right turns. - Emeric Deutsch, Nov 23 2003
Product of A007318 and A105868. - Paul Barry, Nov 15 2005
Number of partitions that fit in an n X n box with Durfee square k. - Franklin T. Adams-Watters, Feb 20 2006
From Peter Bala, Oct 23 2008: (Start)
Narayana numbers of type B. Row n of this triangle is the h-vector of the simplicial complex dual to an associahedron of type B_n (a cyclohedron) [Fomin & Reading, p. 60]. See A063007 for the corresponding f-vectors for associahedra of type B_n. See A001263 for the h-vectors for associahedra of type A_n. The Hilbert transform of this triangular array is A108625 (see A145905 for the definition of this term).
Let A_n be the root lattice generated as a monoid by {e_i - e_j: 0 <= i, j <= n + 1}. Let P(A_n) be the polytope formed by the convex hull of this generating set. Then the rows of this array are the h-vectors of a unimodular triangulation of P(A_n) [Ardila et al.]. A063007 is the corresponding array of f-vectors for these type A_n polytopes. See A086645 for the array of h-vectors for type C_n polytopes and A108558 for the array of h-vectors associated with type D_n polytopes.
(End)
The n-th row consists of the coefficients of the polynomial P_n(t) = Integral_{s = 0..2*Pi} (1 + t^2 - 2*t*cos(s))^n/Pi/2 ds. For example, when n = 3, we get P_3(t) = t^6 + 9*t^4 + 9*t^2 + 1; the coefficients are 1, 9, 9, 1. - Theodore Kolokolnikov, Oct 26 2010
Let E(y) = Sum_{n >= 0} y^n/n!^2 = BesselJ(0, 2*sqrt(-y)). Then this triangle is the generalized Riordan array (E(y), y) with respect to the sequence n!^2 as defined in Wang and Wang. - Peter Bala, Jul 24 2013
From Colin Defant, Sep 16 2018: (Start)
Let s denote West's stack-sorting map. T(n,k) is the number of permutations pi of [n+1] with k descents such that s(pi) avoids the patterns 132, 231, and 321. T(n,k) is also the number of permutations pi of [n+1] with k descents such that s(pi) avoids the patterns 132, 312, and 321.
T(n,k) is the number of permutations of [n+1] with k descents that avoid the patterns 1342, 3142, 3412, and 3421. (End)
The number of convex polyominoes whose smallest bounding rectangle has size (k+1)*(n+1-k) and which contain the lower left corner of the bounding rectangle (directed convex polyominoes). - Günter Rote, Feb 27 2019
Let P be the poset [n] X [n] ordered by the product order. T(n,k) is the number of antichains in P containing exactly k elements. Cf. A063746. - Geoffrey Critzer, Mar 28 2020

Examples

			Pascal's triangle begins
  1
  1  1
  1  2   1
  1  3   3   1
  1  4   6   4   1
  1  5  10  10   5   1
  1  6  15  20  15   6   1
  1  7  21  35  35  21   7   1
...
so the present triangle begins
  1
  1   1
  1   4    1
  1   9    9     1
  1  16   36    16     1
  1  25  100   100    25    1
  1  36  225   400   225   36   1
  1  49  441  1225  1225  441  49   1
...
		

References

  • T. K. Petersen, Eulerian Numbers, Birkhauser, 2015, Chapter 12.
  • J. Riordan, An introduction to combinatorial analysis, Dover Publications, Mineola, NY, 2002, page 191, Problem 15. MR1949650
  • P. G. Tait, On the Linear Differential Equation of the Second Order, Proceedings of the Royal Society of Edinburgh, 9 (1876), 93-98 (see p. 97) [From Tom Copeland, Sep 09 2010, vol number corrected Sep 10 2010]

Crossrefs

Row sums are in A000984. Columns 0-3 are A000012, A000290, A000537, A001249.
Family of polynomials (see A062145): this sequence (c=1), A132813 (c=2), A062196 (c=3), A062145 (c=4), A062264 (c=5), A062190 (c=6).
Cf. A007318, A055133, A116647, A001263, A086645, A063007, A108558, A108625 (Hilbert transform), A145903, A181543, A086645 (logarithmic derivative), A105868 (inverse binomial transform), A093118.

Programs

  • GAP
    Flat(List([0..10],n->List([0..n],k->Binomial(n,k)^2))); # Muniru A Asiru, Mar 30 2018
    
  • Magma
    /* As triangle */ [[Binomial(n, k)^2: k in [0..n]]: n in [0.. 15]]; // Vincenzo Librandi, Dec 15 2016
    
  • Maple
    seq(seq(binomial(n, k)^2, k=0..n), n=0..10);
  • Mathematica
    Table[Binomial[n, k]^2, {n, 0, 11}, {k, 0, n}]//Flatten (* Alonso del Arte, Dec 08 2013 *)
  • Maxima
    create_list(binomial(n,k)^2,n,0,12,k,0,n); /* Emanuele Munarini, Mar 11 2011 */
    
  • Maxima
    T(n,k):=if n=k then 1 else if k=0 then 1 else T(n-1,k)*(n+k)/(n-k)+T(n-1,k-1); /* Vladimir Kruchinin, Oct 18 2014 */
    
  • Maxima
    A(x,y):=1/sqrt(1-2*x-2*x*y+x^2-2*x^2*y+x^2*y^2);
    taylor(x*A(x,y)+x*y*A(x,y)+sqrt(1+4*x^2*y*A(x,y)^2),x,0,7,y,0,7); /* Vladimir Kruchinin, Oct 23 2020 */
    
  • PARI
    {T(n, k) = if( k<0 || k>n, 0, binomial(n, k)^2)}; /* Michael Somos, May 03 2004 */
    
  • PARI
    {T(n,k)=polcoeff(polcoeff(sum(m=0,n,(2*m)!/m!^2*x^(2*m)*y^m/(1-x-x*y+x*O(x^n))^(2*m+1)),n,x),k,y)} \\ Paul D. Hanna, Oct 31 2010
    
  • Python
    def A008459(n): return comb(r:=(m:=isqrt(k:=n+1<<1))-(k<=m*(m+1)),n-comb(r+1,2))**2 # Chai Wah Wu, Nov 12 2024

Formula

T(n,k) = A007318(n,k)^2. - Sean A. Irvine, Mar 29 2018
E.g.f.: exp((1+y)*x)*BesselI(0, 2*sqrt(y)*x). - Vladeta Jovovic, Nov 17 2003
G.f.: 1/sqrt(1-2*x-2*x*y+x^2-2*x^2*y+x^2*y^2); g.f. for row n: (1-t)^n P_n[(1+t)/(1-t)] where the P_n's are the Legendre polynomials. - Emeric Deutsch, Nov 23 2003 [The original version of the bivariate g.f. has been modified with the roles of x and y interchanged so that now x corresponds to n and y to k. - Petros Hadjicostas, Oct 22 2017]
G.f. for column k is Sum_{j = 0..k} C(k, j)^2*x^(k+j)/(1 - x)^(2*k+1). - Paul Barry, Nov 15 2005
Column k has g.f. (x^k)*Legendre_P(k, (1+x)/(1-x))/(1 - x)^(k+1) = (x^k)*Sum_{j = 0..k} C(k, j)^2*x^j/(1 - x)^(2*k+1). - Paul Barry, Nov 19 2005
Let E be the operator D*x*D, where D denotes the derivative operator d/dx. Then (1/n!^2) * E^n(1/(1 - x)) = (row n generating polynomial)/(1 - x)^(2*n+1) = Sum_{k >= 0} binomial(n+k, k)^2*x^k. For example, when n = 3 we have (1/3!)^2*E^3(1/(1 - x)) = (1 + 9*x + 9*x^2 + x^3)/(1 - x)^7 = (1/3!)^2 * Sum_{k >= 0} ((k+1)*(k+2)*(k+3))^2*x^k. - Peter Bala, Oct 23 2008
G.f.: A(x, y) = Sum_{n >= 0} (2*n)!/n!^2 * x^(2*n)*y^n/(1 - x - x*y)^(2*n+1). - Paul D. Hanna, Oct 31 2010
From Peter Bala, Jul 24 2013: (Start)
Let E(y) = Sum_{n >= 0} y^n/n!^2 = BesselJ(0, 2*sqrt(-y)). Generating function: E(y)*E(x*y) = 1 + (1 + x)*y + (1 + 4*x + x^2)*y^2/2!^2 + (1 + 9*x + 9*x^2 + x^3)*y^3/3!^2 + .... Cf. the unsigned version of A021009 with generating function exp(y)*E(x*y).
The n-th power of this array has the generating function E(y)^n*E(x*y). In particular, the matrix inverse A055133 has the generating function E(x*y)/E(y). (End)
T(n,k) = T(n-1,k)*(n+k)/(n-k) + T(n-1,k-1), T(n,0) = T(n,n) = 1. - Vladimir Kruchinin, Oct 18 2014
Observe that the recurrence T(n,k) = T(n-1,k)*(n+k)/(n-k) - T(n-1,k-1), for n >= 2 and 1 <= k < n, with boundary conditions T(n,0) = T(n,n) = 1 gives Pascal's triangle A007318. - Peter Bala, Dec 21 2014
n-th row polynomial R(n, x) = [z^n] (1 + (1 + x)*z + x*z^2)^n. Note that 1/n*[z^(n-1)] (1 + (1 + x)*z + x*z^2)^n gives the row polynomials of A001263. - Peter Bala, Jun 24 2015
Binomial transform of A105868. If G(x,t) = 1/sqrt(1 - 2*(1 + t)*x + (1 - t)^2*x^2) denotes the o.g.f. of this array then 1 + x*d/dx log(G(x,t)) = 1 + (1 + t)*x + (1 + 6*t + t^2)*x^2 + ... is the o.g.f. for A086645. - Peter Bala, Sep 06 2015
T(n,k) = Sum_{i=0..n} C(n-i,k)*C(n,i)*C(n+i,i)*(-1)^(n-i-k). - Vladimir Kruchinin, Jan 14 2018
G.f. satisfies A(x,y) = x*A(x,y)+x*y*A(x,y)+sqrt(1+4*x^2*y*A(x,y)^2). - Vladimir Kruchinin, Oct 23 2020
G.f. satisfies the differential equation y * d^2(A(x,y))/dy^2 - x^2 * d^2(x*A(x,y))/dx^2 + 2*x^2* A(x,y)^3 = 0. - Sergii Voloshyn, Mar 07 2025
T(n,k) = Sum_{i=0..n} C(2*n+1,i)*C(n+k-i,n)^2*(-1)^i. - Natalia L. Skirrow, Apr 14 2025

A086020 a(n) = Sum_(i=1..n) binomial(i+2,3)^2 [ Sequential sums of the tetragonal numbers or "tetras" (pyramidal, square) raised to power 2 (drawn from the 4th diagonal - left or right - of Pascal's Triangle) ].

Original entry on oeis.org

1, 17, 117, 517, 1742, 4878, 11934, 26334, 53559, 101959, 183755, 316251, 523276, 836876, 1299276, 1965132, 2904093, 4203693, 5972593, 8344193, 11480634, 15577210, 20867210, 27627210, 36182835, 46915011, 60266727, 76750327
Offset: 1

Views

Author

André F. Labossière, Jul 17 2003

Keywords

Comments

Kekulé numbers for certain benzenoids (see the Cyvin-Gutman reference, p. 243; expression in (13.26) yields same sequence with offset 0). - Emeric Deutsch, Aug 02 2005
Partial sums of A001249. - R. J. Mathar, Aug 19 2008

Examples

			a(8) = Sum_{i=1..8} binomial(i+2,3)^2 = (20*(8^7) + 210*(8^6) + 854*(8^5) + 1680*(8^4) + 1610*(8^3) + 630*(8^2) + 36*8)/7! = 26334.
		

Crossrefs

Programs

  • Magma
    [n*(n+1)*(n+2)*(n+3)*(2*n+3)*(5*n^2+15*n+1)/2520: n in [1..30]]; // G. C. Greubel, Nov 22 2017
  • Maple
    a:=n->n*(n+1)*(n+2)*(n+3)*(2*n+3)*(5*n^2+15*n+1)/2520: seq(a(n),n=1..31); # Emeric Deutsch
  • Mathematica
    Accumulate[Binomial[Range[30]+2,3]^2]  (* Harvey P. Dale, Mar 24 2011 *)
    LinearRecurrence[{8,-28,56,-70,56,-28,8,-1},{1,17,117,517,1742,4878, 11934, 26334},30] (* Harvey P. Dale, Aug 17 2014 *)
  • PARI
    a(n)=n*(n+1)*(n+2)*(n+3)*(2*n+3)*(5*n^2+15*n+1)/2520 \\ Charles R Greathouse IV, May 18 2015
    

Formula

a(n) = Sum_(i=1..n) binomial(i+2, 3)^2.
a(n) = ( C(n+3, 4)/35 )*( 35 + 84*C(n-1, 1) + 70*C(n-1, 2) + 20*C(n-1, 3) ).
a(n) = n*(n+1)*(n+2)*(n+3)*(2*n+3)(5*n^2 + 15*n + 1)/2520. - Emeric Deutsch, Aug 02 2005
O.g.f: x*(1+x)*(1 + 8*x + x^2)/(1-x)^8. - R. J. Mathar, Aug 19 2008

A033455 Convolution of nonzero squares A000290 with themselves.

Original entry on oeis.org

1, 8, 34, 104, 259, 560, 1092, 1968, 3333, 5368, 8294, 12376, 17927, 25312, 34952, 47328, 62985, 82536, 106666, 136136, 171787, 214544, 265420, 325520, 396045, 478296, 573678, 683704, 809999, 954304, 1118480, 1304512, 1514513, 1750728, 2015538, 2311464
Offset: 1

Views

Author

Keywords

Comments

Total area of all square regions from an n X n grid. E.g., at n = 3, there are nine individual squares, four 2 X 2's and one 3 X 3, total area 9 + 16 + 9 = 34, hence a(3) = 34. - Jon Perry, Jul 29 2003
If X is an n-set and Y and Z disjoint 2-subsets of X then a(n) is equal to the number of 7-subsets of X intersecting both Y and Z. - Milan Janjic, Aug 26 2007
Every fourth term is odd. However, there are no primes in the sequence. - Zak Seidov, Feb 28 2011
-120*a(n) is the real part of (n + n*i)*(n + 2 + n*i)*(n + (n + 2)i)*(n + 2+(n + 2)*i)*(n + 1 + (n + 1)*i), where i = sqrt(-1). - Jon Perry, Feb 05 2014
The previous formula rephrases the factorization of the 5th-order polynomial a(n) = (n+1)*((n+1)^4-1) = (n+1)*A123864(n+1) based on the factorization in A123865. - R. J. Mathar, Feb 08 2014

Crossrefs

Programs

Formula

a(n-1) = n*(n^4 - 1)/30 = A061167(n)/30. - Henry Bottomley, Apr 18 2001
G.f.: x*(1+x)^2/(1-x)^6. - Philippe Deléham, Feb 21 2012
a(n) = Sum_{k=1..n+1} k^2*(n+1-k)^2. - Kolosov Petro, Feb 07 2019
E.g.f.: x*(30 +90*x +65*x^2 +15*x^3 +x^4)*exp(x)/30. - G. C. Greubel, Jul 05 2019

Extensions

More terms from Vincenzo Librandi, Mar 24 2014

A250853 T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with nondecreasing x(i,j)-x(i,j-1) in the i direction and nondecreasing min(x(i,j),x(i-1,j)) in the j direction.

Original entry on oeis.org

100, 400, 543, 1225, 2457, 2670, 3136, 8037, 13097, 12311, 7056, 21436, 44797, 63631, 54410, 14400, 49599, 123016, 223933, 291165, 233683, 27225, 103293, 290646, 626416, 1043885, 1280447, 983950, 48400, 198297, 614965, 1499679, 2955136
Offset: 1

Views

Author

R. H. Hardin, Nov 28 2014

Keywords

Comments

Table starts
......100.......400.......1225.......3136........7056.......14400.......27225
......543......2457.......8037......21436.......49599......103293......198297
.....2670.....13097......44797.....123016......290646......614965.....1195457
....12311.....63631.....223933.....626416.....1499679.....3204951.....6279401
....54410....291165....1043885....2955136.....7134786....15344785....30214465
...233683...1280447....4648157...13263136....32201019....69543783...137379337
...983950...5480917...20067117...57570016...140301126...303858745...601566177
..4085631..23024631...84805533..244213216...596722599..1294875471..2567402601
.16796370..95448605..353060845.1019415136..2495502666..5422612945.10763029505
.68555723.391939087.1454214877.4206874336.10311967539.22429374423.44552408777

Examples

			Some solutions for n=3 k=4
..2..2..0..0..0....1..2..3..2..2....2..2..1..0..0....3..2..1..1..1
..0..0..0..0..0....0..1..2..2..3....0..0..0..0..0....0..0..0..0..0
..1..1..1..1..1....0..1..2..2..3....1..1..1..1..3....0..0..1..1..2
..0..1..1..1..3....0..1..2..2..3....0..0..0..1..3....0..0..1..1..2
		

Crossrefs

Row 1 is A001249(n+1)

Formula

Empirical T(n,k) = (((31/36)*k^6+(25/2)*k^5+(1229/18)*k^4+(620/3)*k^3+(10759/36)*k^2+(1181/6)*k+48)*4^n -((5/3)*k^6+(133/6)*k^5+(320/3)*k^4+(1717/6)*k^3+(944/3)*k^2+(344/3)*k)*3^n +(k^6+12*k^5+47*k^4+103*k^3+54*k^2-13*k)*2^n -((1/9)*k^6+(3/2)*k^5+(25/9)*k^4+(13/6)*k^3-(89/9)*k^2+(4/3)*k))/12
Empirical for column k:
k=1: a(n) = 10*a(n-1) -35*a(n-2) +50*a(n-3) -24*a(n-4); a(n) = (832*4^n-846*3^n+204*2^n+2)/12
k=2: a(n) = 10*a(n-1) -35*a(n-2) +50*a(n-3) -24*a(n-4); a(n) = (4838*4^n-6300*3^n+2214*2^n-80)/12
k=3: a(n) = 10*a(n-1) -35*a(n-2) +50*a(n-3) -24*a(n-4); a(n) = (18104*4^n-26144*3^n+10680*2^n-644)/12
k=4: a(n) = 10*a(n-1) -35*a(n-2) +50*a(n-3) -24*a(n-4); a(n) = (52650*4^n-80640*3^n+35820*2^n-2688)/12
k=5: a(n) = 10*a(n-1) -35*a(n-2) +50*a(n-3) -24*a(n-4); a(n) = (129528*4^n-206190*3^n+96660*2^n-8190)/12
k=6: a(n) = 10*a(n-1) -35*a(n-2) +50*a(n-3) -24*a(n-4); a(n) = (282492*4^n-462196*3^n+224994*2^n-20568)/12
k=7: a(n) = 10*a(n-1) -35*a(n-2) +50*a(n-3) -24*a(n-4); a(n) = (562288*4^n-939120*3^n+470064*2^n-45220)/12
Empirical for row n:
n=1: a(n) = (1/36)*n^6 + (1/2)*n^5 + (133/36)*n^4 + (43/3)*n^3 + (277/9)*n^2 + (104/3)*n + 16
n=2: a(n) = (2/9)*n^6 + (47/12)*n^5 + (953/36)*n^4 + (1141/12)*n^3 + (6527/36)*n^2 + 172*n + 64
n=3: a(n) = (3/2)*n^6 + (74/3)*n^5 + (621/4)*n^4 + (3161/6)*n^3 + (3691/4)*n^2 + 783*n + 256
n=4: a(n) = (76/9)*n^6 + (1595/12)*n^5 + (28765/36)*n^4 + (31373/12)*n^3 + (155683/36)*n^2 + (10223/3)*n + 1024
n=5: a(n) = (763/18)*n^6 + (1949/3)*n^5 + (136493/36)*n^4 + (72691/6)*n^3 + (693923/36)*n^2 + (43319/3)*n + 4096
n=6: a(n) = 198*n^6 + (35807/12)*n^5 + (204911/12)*n^4 + (214827/4)*n^3 + (998209/12)*n^2 + (180451/3)*n + 16384
n=7: a(n) = (15887/18)*n^6 + (39464/3)*n^5 + (2674189/36)*n^4 + (462227/2)*n^3 + (12645859/36)*n^2 + (743119/3)*n + 65536

A223864 T(n,k)=Number of nXk 0..3 arrays with rows and antidiagonals unimodal and columns nondecreasing.

Original entry on oeis.org

4, 16, 10, 50, 100, 20, 130, 684, 400, 35, 296, 3526, 4884, 1225, 56, 610, 14751, 41682, 24199, 3136, 84, 1163, 52591, 273959, 315124, 93731, 7056, 120, 2083, 165212, 1477240, 3017129, 1771012, 303560, 14400, 165, 3544, 468292, 6818350, 22852913
Offset: 1

Views

Author

R. H. Hardin Mar 28 2013

Keywords

Comments

Table starts
...4....16.......50.......130.........296...........610...........1163
..10...100......684......3526.......14751.........52591.........165212
..20...400.....4884.....41682......273959.......1477240........6818350
..35..1225....24199....315124.....3017129......22852913......144081276
..56..3136....93731...1771012....23738426.....243933798.....2030417942
..84..7056...303560...8008548...145947740....1989679315....21476594002
.120.14400...857696..30627033...740441932...13140481520...181330154458
.165.27225..2175884.102479569..3217594840...73068868012..1271807435844
.220.48400..5058530.307435001.12305144319..352040804450..7630189031428
.286.81796.10940664.842078930.42270004211.1502130487437.40055722078772

Examples

			Some solutions for n=3 k=4
..0..0..0..0....0..2..1..1....0..1..3..2....0..2..2..0....0..1..1..3
..0..0..0..1....0..2..3..1....0..2..3..2....1..3..3..2....0..1..3..3
..2..3..2..2....0..2..3..3....1..3..3..3....3..3..3..2....1..3..3..3
		

Crossrefs

Column 1 is A000292(n+1)
Column 2 is A001249
Row 1 is A223659

Formula

Empirical: columns k=1..7 are polynomials of degree 3*k for n>0,0,0,1,2,4,6
Empirical: rows n=1..7 are polynomials of degree 6*n

A224173 T(n,k) = number of n X k 0..3 arrays with rows, diagonals and antidiagonals unimodal and columns nondecreasing.

Original entry on oeis.org

4, 16, 10, 50, 100, 20, 130, 684, 400, 35, 296, 3526, 4739, 1225, 56, 610, 14751, 38561, 22988, 3136, 84, 1163, 52591, 242114, 272130, 87878, 7056, 120, 2083, 165212, 1253770, 2335459, 1460836, 282372, 14400, 165, 3544, 468292, 5588411, 15925611
Offset: 1

Views

Author

R. H. Hardin, Mar 31 2013

Keywords

Examples

			Table starts:
    4    16       50       130         296          610           1163
   10   100      684      3526       14751        52591         165212
   20   400     4739     38561      242114      1253770        5588411
   35  1225    22988    272130     2335459     15925611       91494280
   56  3136    87878   1460836    16625026    143558572     1012166273
   84  7056   282372   6425876    95808564   1038484760     8857798353
  120 14400   794220  24197608   468021427   6360047093    65713691148
  165 27225  2010035  80350989  1994287334  33901838632   426013124302
  220 48400  4668304 240416852  7568051210 160168789130  2451904991177
  286 81796 10095924 658890738 25994968917 680269560125 12667946702827
  ...
Some solutions for n=3 k=4
..0..0..1..0....0..0..1..2....0..0..3..0....0..2..0..0....0..3..3..1
..1..3..3..1....0..1..3..2....3..3..3..1....1..2..0..0....1..3..3..1
..1..3..3..3....0..3..3..2....3..3..3..2....2..2..1..0....1..3..3..3
		

Crossrefs

Main diagonal is A224167.
Columns 1..7 are A000292(n+1), A001249, A224168, A224169, A224170, A224171, A224172.
Cf. A223838.

Formula

Empirical: columns k=1..7 are polynomials of degree 3*k for n>0,0,0,3,6,9,12.
Empirical: rows n=1..5 are polynomials of degree 6*n for k>0,0,0,2,6.

Extensions

Name corrected by Andrew Howroyd, Mar 18 2025

A223987 T(n,k)=Number of nXk 0..3 arrays with rows unimodal and columns nondecreasing.

Original entry on oeis.org

4, 16, 10, 50, 100, 20, 130, 684, 400, 35, 296, 3526, 5029, 1225, 56, 610, 14751, 44803, 25410, 3136, 84, 1163, 52591, 308470, 358118, 99634, 7056, 120, 2083, 165212, 1738756, 3770722, 2086196, 325120, 14400, 165, 3544, 468292, 8350154, 31585056
Offset: 1

Views

Author

R. H. Hardin Mar 30 2013

Keywords

Comments

Table starts
...4....16.......50........130.........296...........610...........1163
..10...100......684.......3526.......14751.........52591.........165212
..20...400.....5029......44803......308470.......1738756........8350154
..35..1225....25410.....358118.....3770722......31585056......219861244
..56..3136....99634....2086196....31831914.....378122264.....3661410444
..84..7056...325120....9647292...204647416....3322756326....43307637038
.120.14400...922768...37395816..1067023886...22985966340...392525216516
.165.27225..2346883..126087157..4710529013..131366850521..2873859236297
.220.48400..5462600..379654704.18159308422..642224541548.17659521902693
.286.81796.11818092.1040942916.62548820489.2756467192963.93729371629362

Examples

			Some solutions for n=3 k=4
..0..2..1..1....0..0..2..0....0..1..1..0....1..2..0..0....2..2..2..0
..0..2..2..1....1..1..2..0....0..3..2..1....1..2..2..0....3..2..2..1
..1..3..3..3....2..3..2..1....3..3..2..1....2..3..3..2....3..2..2..1
		

Crossrefs

Column 1 is A000292(n+1)
Column 2 is A001249
Row 1 is A223659
Row 2 is A223865

Formula

Empirical: columns k=1..7 are polynomials of degree 3*k
Empirical: rows n=1..7 are polynomials of degree 6*n

A224024 T(n,k)=Number of nXk 0..3 arrays with rows nondecreasing and antidiagonals unimodal.

Original entry on oeis.org

4, 10, 16, 20, 100, 64, 35, 400, 1000, 256, 56, 1225, 6796, 10000, 1024, 84, 3136, 32523, 112436, 100000, 4096, 120, 7056, 122523, 772683, 1859020, 1000000, 16384, 165, 14400, 387729, 4002738, 17735200, 30756756, 10000000, 65536, 220, 27225, 1074167
Offset: 1

Views

Author

R. H. Hardin Mar 30 2013

Keywords

Comments

Table starts
.......4..........10............20..............35...............56
......16.........100...........400............1225.............3136
......64........1000..........6796...........32523...........122523
.....256.......10000........112436..........772683..........4002738
....1024......100000.......1859020........17735200........120352359
....4096.....1000000......30756756.......403836633.......3491241557
...16384....10000000.....508916456......9186127249......99853876444
...65536...100000000....8420768936....208983591829....2841637297963
..262144..1000000000..139333478144...4754911670136...80738139650660
.1048576.10000000000.2305467501680.108190494364824.2292943314015674

Examples

			Some solutions for n=3 k=4
..3..3..3..3....1..3..3..3....0..0..0..2....1..1..2..2....0..0..1..1
..0..2..3..3....0..2..3..3....2..2..3..3....0..0..1..2....0..1..3..3
..1..1..1..1....0..0..1..1....0..2..2..3....0..0..2..3....1..1..3..3
		

Crossrefs

Column 1 is A000302
Column 2 is A011557
Row 1 is A000292(n+1)
Row 2 is A001249

Formula

Empirical: columns k=1..7 have recurrences of order 1,1,7,10,19,25,41
Empirical: rows n=1..7 are polynomials of degree 3*n for k>0,0,1,2,3,4,5

A224391 T(n,k)=Number of nXk 0..3 arrays with diagonals and antidiagonals unimodal and rows nondecreasing.

Original entry on oeis.org

4, 10, 16, 20, 100, 64, 35, 400, 1000, 256, 56, 1225, 6094, 10000, 1024, 84, 3136, 27790, 86701, 100000, 4096, 120, 7056, 102232, 497958, 1268572, 1000000, 16384, 165, 14400, 319769, 2332222, 8573507, 18794636, 10000000, 65536, 220, 27225, 881519
Offset: 1

Views

Author

R. H. Hardin Apr 05 2013

Keywords

Comments

Table starts
.......4..........10...........20.............35..............56
......16.........100..........400...........1225............3136
......64........1000.........6094..........27790..........102232
.....256.......10000........86701.........497958.........2332222
....1024......100000......1268572........8573507........45648753
....4096.....1000000.....18794636......152271025.......879830242
...16384....10000000....279128617.....2780848289.....17642791909
...65536...100000000...4142692993....51325449985....365858453951
..262144..1000000000..61481903024...949582166068...7713944320142
.1048576.10000000000.912523782542.17572045403455.163629606236587

Examples

			Some solutions for n=3 k=4
..0..1..1..1....0..1..1..3....1..2..3..3....2..2..3..3....0..0..0..1
..2..2..2..2....0..1..3..3....0..2..2..2....0..3..3..3....0..2..2..3
..1..3..3..3....0..2..3..3....1..1..1..1....0..0..1..2....3..3..3..3
		

Crossrefs

Column 1 is A000302
Column 2 is A011557
Row 1 is A000292(n+1)
Row 2 is A001249

Formula

Empirical for column k:
k=1: a(n) = 4*a(n-1)
k=2: a(n) = 10*a(n-1)
k=3: [order 15]
k=4: [order 47]
Empirical: rows n=1..6 are polynomials of degree 3*n for k>0,0,1,4,7,10
Showing 1-10 of 19 results. Next