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.

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A213500 Rectangular array T(n,k): (row n) = b**c, where b(h) = h, c(h) = h + n - 1, n >= 1, h >= 1, and ** = convolution.

Original entry on oeis.org

1, 4, 2, 10, 7, 3, 20, 16, 10, 4, 35, 30, 22, 13, 5, 56, 50, 40, 28, 16, 6, 84, 77, 65, 50, 34, 19, 7, 120, 112, 98, 80, 60, 40, 22, 8, 165, 156, 140, 119, 95, 70, 46, 25, 9, 220, 210, 192, 168, 140, 110, 80, 52, 28, 10, 286, 275, 255, 228, 196, 161, 125, 90
Offset: 1

Views

Author

Clark Kimberling, Jun 14 2012

Keywords

Comments

Principal diagonal: A002412.
Antidiagonal sums: A002415.
Row 1: (1,2,3,...)**(1,2,3,...) = A000292.
Row 2: (1,2,3,...)**(2,3,4,...) = A005581.
Row 3: (1,2,3,...)**(3,4,5,...) = A006503.
Row 4: (1,2,3,...)**(4,5,6,...) = A060488.
Row 5: (1,2,3,...)**(5,6,7,...) = A096941.
Row 6: (1,2,3,...)**(6,7,8,...) = A096957.
...
In general, the convolution of two infinite sequences is defined from the convolution of two n-tuples: let X(n) = (x(1),...,x(n)) and Y(n)=(y(1),...,y(n)); then X(n)**Y(n) = x(1)*y(n)+x(2)*y(n-1)+...+x(n)*y(1); this sum is the n-th term in the convolution of infinite sequences:(x(1),...,x(n),...)**(y(1),...,y(n),...), for all n>=1.
...
In the following guide to related arrays and sequences, row n of each array T(n,k) is the convolution b**c of the sequences b(h) and c(h+n-1). The principal diagonal is given by T(n,n) and the n-th antidiagonal sum by S(n). In some cases, T(n,n) or S(n) differs in offset from the listed sequence.
b(h)........ c(h)........ T(n,k) .. T(n,n) .. S(n)
h .......... h .......... A213500 . A002412 . A002415
h .......... h^2 ........ A212891 . A213436 . A024166
h^2 ........ h .......... A213503 . A117066 . A033455
h^2 ........ h^2 ........ A213505 . A213546 . A213547
h .......... h*(h+1)/2 .. A213548 . A213549 . A051836
h*(h+1)/2 .. h .......... A213550 . A002418 . A005585
h*(h+1)/2 .. h*(h+1)/2 .. A213551 . A213552 . A051923
h .......... h^3 ........ A213553 . A213554 . A101089
h^3 ........ h .......... A213555 . A213556 . A213547
h^3 ........ h^3 ........ A213558 . A213559 . A213560
h^2 ........ h*(h+1)/2 .. A213561 . A213562 . A213563
h*(h+1)/2 .. h^2 ........ A213564 . A213565 . A101094
2^(h-1) .... h .......... A213568 . A213569 . A047520
2^(h-1) .... h^2 ........ A213573 . A213574 . A213575
h .......... Fibo(h) .... A213576 . A213577 . A213578
Fibo(h) .... h .......... A213579 . A213580 . A053808
Fibo(h) .... Fibo(h) .... A067418 . A027991 . A067988
Fibo(h+1) .. h .......... A213584 . A213585 . A213586
Fibo(n+1) .. Fibo(h+1) .. A213587 . A213588 . A213589
h^2 ........ Fibo(h) .... A213590 . A213504 . A213557
Fibo(h) .... h^2 ........ A213566 . A213567 . A213570
h .......... -1+2^h ..... A213571 . A213572 . A213581
-1+2^h ..... h .......... A213582 . A213583 . A156928
-1+2^h ..... -1+2^h ..... A213747 . A213748 . A213749
h .......... 2*h-1 ...... A213750 . A007585 . A002417
2*h-1 ...... h .......... A213751 . A051662 . A006325
2*h-1 ...... 2*h-1 ...... A213752 . A100157 . A071238
2*h-1 ...... -1+2^h ..... A213753 . A213754 . A213755
-1+2^h ..... 2*h-1 ...... A213756 . A213757 . A213758
2^(n-1) .... 2*h-1 ...... A213762 . A213763 . A213764
2*h-1 ...... Fibo(h) .... A213765 . A213766 . A213767
Fibo(h) .... 2*h-1 ...... A213768 . A213769 . A213770
Fibo(h+1) .. 2*h-1 ...... A213774 . A213775 . A213776
Fibo(h) .... Fibo(h+1) .. A213777 . A001870 . A152881
h .......... 1+[h/2] .... A213778 . A213779 . A213780
1+[h/2] .... h .......... A213781 . A213782 . A005712
1+[h/2] .... [(h+1)/2] .. A213783 . A213759 . A213760
h .......... 3*h-2 ...... A213761 . A172073 . A002419
3*h-2 ...... h .......... A213771 . A213772 . A132117
3*h-2 ...... 3*h-2 ...... A213773 . A214092 . A213818
h .......... 3*h-1 ...... A213819 . A213820 . A153978
3*h-1 ...... h .......... A213821 . A033431 . A176060
3*h-1 ...... 3*h-1 ...... A213822 . A213823 . A213824
3*h-1 ...... 3*h-2 ...... A213825 . A213826 . A213827
3*h-2 ...... 3*h-1 ...... A213828 . A213829 . A213830
2*h-1 ...... 3*h-2 ...... A213831 . A213832 . A212560
3*h-2 ...... 2*h-1 ...... A213833 . A130748 . A213834
h .......... 4*h-3 ...... A213835 . A172078 . A051797
4*h-3 ...... h .......... A213836 . A213837 . A071238
4*h-3 ...... 2*h-1 ...... A213838 . A213839 . A213840
2*h-1 ...... 4*h-3 ...... A213841 . A213842 . A213843
2*h-1 ...... 4*h-1 ...... A213844 . A213845 . A213846
4*h-1 ...... 2*h-1 ...... A213847 . A213848 . A180324
[(h+1)/2] .. [(h+1)/2] .. A213849 . A049778 . A213850
h .......... C(2*h-2,h-1) A213853
...
Suppose that u = (u(n)) and v = (v(n)) are sequences having generating functions U(x) and V(x), respectively. Then the convolution u**v has generating function U(x)*V(x). Accordingly, if u and v are homogeneous linear recurrence sequences, then every row of the convolution array T satisfies the same homogeneous linear recurrence equation, which can be easily obtained from the denominator of U(x)*V(x). Also, every column of T has the same homogeneous linear recurrence as v.

Examples

			Northwest corner (the array is read by southwest falling antidiagonals):
  1,  4, 10, 20,  35,  56,  84, ...
  2,  7, 16, 30,  50,  77, 112, ...
  3, 10, 22, 40,  65,  98, 140, ...
  4, 13, 28, 50,  80, 119, 168, ...
  5, 16, 34, 60,  95, 140, 196, ...
  6, 19, 40, 70, 110, 161, 224, ...
T(6,1) = (1)**(6) = 6;
T(6,2) = (1,2)**(6,7) = 1*7+2*6 = 19;
T(6,3) = (1,2,3)**(6,7,8) = 1*8+2*7+3*6 = 40.
		

Crossrefs

Cf. A000027.

Programs

  • Mathematica
    b[n_] := n; c[n_] := n
    t[n_, k_] := Sum[b[k - i] c[n + i], {i, 0, k - 1}]
    TableForm[Table[t[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[t[n - k + 1, k], {n, 12}, {k, n, 1, -1}]]
    r[n_] := Table[t[n, k], {k, 1, 60}]  (* A213500 *)
  • PARI
    t(n,k) = sum(i=0, k - 1, (k - i) * (n + i));
    tabl(nn) = {for(n=1, nn, for(k=1, n, print1(t(k,n - k + 1),", ");); print(););};
    tabl(12) \\ Indranil Ghosh, Mar 26 2017
    
  • Python
    def t(n, k): return sum((k - i) * (n + i) for i in range(k))
    for n in range(1, 13):
        print([t(k, n - k + 1) for k in range(1, n + 1)]) # Indranil Ghosh, Mar 26 2017

Formula

T(n,k) = 4*T(n,k-1) - 6*T(n,k-2) + 4*T(n,k-3) - T(n,k-4).
T(n,k) = 2*T(n-1,k) - T(n-2,k).
G.f. for row n: x*(n - (n - 1)*x)/(1 - x)^4.

A156927 FP3 polynomials related to the generating functions of the columns of the A156921 matrix.

Original entry on oeis.org

1, 1, 1, -6, 29, 31, -283, 245, 298, -286, -108, 119, -3106, 29469, -104585, -220481, 3601363, -15487305, 34949165, -39821950, 4356011, 46881744, -51274736, 9005908, 14663472, -5205168, -1456704, -20736
Offset: 0

Views

Author

Johannes W. Meijer, Feb 20 2009

Keywords

Comments

For the matrix of the FP1 polynomials see A156921. The coefficients in the columns of this matrix are the powers of z^m, m=0, 1, 2, ... . The columns are numbered 1, 2, 3... .
The GF3(z;m) generate the sequences of the z^m coefficients. The general structure of the GF3(z;m) is given below.
The FP3(z,m) in the numerator of the GF3(z;m) is a polynomial of a certain degree, let's say k3. The (k3+1) coefficients of this polynomial can be determined one by one by comparing the series expansion of the FP3(z,m) with the values of the powers of z^m in column (m+1). These values can be generated with the GF1 formulas, see A156921.
An appropriate name for the polynomials FP3(z;m) in the numerators of the GF(3;m) seems to be the flower polynomials of the third kind, the FP3, because the zero patterns of these polynomials look like flowers. The zero patterns of the FP3 and the FP4, see A156933, resemble each other closely and look like the zero patterns of the FP1 and FP2.
The sequence of the (k3+1) number of terms of the FP3(z;m) polynomials for m from 0 to 11 is 1, 2, 8, 17, 29, 45, 63, 84, 109, 137, 167, 200.

Examples

			The first few rows of the "triangle" of the FP3(z,m) coefficients are:
  [1]
  [1, 1]
  [-6, 29, 31, -283, 245, 298, -286, -108]
The first few FP3 polynomials are:
  FP3(z; m=0) = 1
  FP3(z; m=1) = (1+z)
  FP3(z; m=2) = (-6+29*z+31*z^2-283*z^3+245*z^4+298*z^5-286*z^6-108*z^7)
Some GF3(z;m) are:
  GF3(z;m=1) = z^2*(1+z)/((1-z)^4*(1-2*z))
  GF3(z;m=2) = z^2*(-6+29*z+31*z^2-283*z^3+245*z^4+298*z^5-286*z^6-108*z^7)/((1-z)^7*(1-2*z)^4*(1-3*z))
		

Crossrefs

For the first few GF3's see A156928, A156929, A156930, A156931.
Row sums A156932.
For the polynomials in the denominators of the GF3(z;m) see A157704.

Formula

G.f.: GF3(z;m):= z^p*FP3(z;m)/Product_{k=0..m} (1-(k+1)*z)^(1+3*k).

A156929 G.f. of the z^2 coefficients of the FP1 in the third column of the A156921 matrix.

Original entry on oeis.org

-6, -79, -515, -2255, -7321, -17280, -20052, 73530, 683280, 3482667, 14574887, 55023247, 194872885, 661036370, 2174736558, 6996176016, 22133771190, 69145507605, 213941135265, 657095902685
Offset: 2

Views

Author

Johannes W. Meijer, Feb 20 2009

Keywords

Crossrefs

Equals third column of A156921
Other columns A156928, A156930, A156931

Formula

a(n)=18*a(n-1)-146*a(n-2)+706*a(n-3)-2268*a(n-4)+5102*a(n-5)-8246*a(n-6)+9654*a(n-7)-8131*a(n-8)+4808*a(n-9)-1896*a(n-10)+448*a(n-11)-48*a(n-12)
a(n)= 1/18*n^6+1/2*n^5+169/72*n^4-n^3*2^(n+1)+29/4*n^3-9*n^2*2^n+ 1123/72*n^2 -37*n*2^n+ 101/4*n-90*2^n+135/2*3^n+45/2
G.f.: GF3(z;m=2) = z^2*(-6+29*z+31*z^2-283*z^3+245*z^4+298*z^5-286*z^6-108*z^7)/((1-z)^7*(1-2*z)^4*(1-3*z))

A156930 G.f. of the z^3 coefficients of the FP1 in the fourth column of the A156921 matrix.

Original entry on oeis.org

119, 1654, 5784, -57421, -974120, -8191112, -51264392, -266367722, -1204269647, -4832097594, -17187443308, -52433219783, -120342975558, -58288009528, 1603731045044, 13940518848356
Offset: 3

Views

Author

Johannes W. Meijer, Feb 20 2009

Keywords

Crossrefs

Equals fourth column of A156921
Other columns A156928, A156929, A156931

Formula

a(n)=40*a(n-1)-755*a(n-2)+8946*a(n-3)-74677*a(n-4)+467156*a(n-5)-2274363*a(n-6)+8833486*a(n-7)-27833039*a(n-8)+71958408*a(n-9)-153781873*a(n-10)+272810702*a(n-11)-402324879*a(n-12)+492639700*a(n-13)-498877265*a(n-14)+414825042*a(n-15)-280100140*a(n-16)+151065320*a(n-17)-63500432*a(n-18)+20037984*a(n-19)-4463424*a(n-20)+625536*a(n-21)-41472*a(n-22)
G.f.: GF3(z;m=3) = z^3*( 119-3106*z+29469*z^2-104585*z^3-220481*z^4+3601363*z^5-15487305*z^6+34949165*z^7-39821950*z^8+4356011*z^9+46881744*z^10-51274736*z^11+ 9005908*z^12+14663472*z^13-5205168*z^14-1456704*z^15-20736*z^16)/((1-z)^10*(1-2*z)^7*(1-3*z)^4*(1-4*z))

A156931 G.f. of the z^4 coefficients of the FP1 in the fifth column of the A156921 matrix.

Original entry on oeis.org

126, 8689, 300930, 5663483, 69028169, 613038531, 4234224501, 23275739871, 98332765273, 250304681662, -554375755759, -13379311589392, -119762221369238, -826135093245122, -4949174987335110
Offset: 3

Views

Author

Johannes W. Meijer, Feb 20 2009

Keywords

Crossrefs

Equals fifth column of A156921
Other columns A156928, A156929, A156930

Formula

G.f.: GF3(z;m=4) = z^3*(126-761*z-9285*z^2-1277673*z^3+46183284*z^4-696765279*z^5+5823518147*z^6-25089694147*z^7-12711864696*z^8+988743755109*z^9-7652560832135*z^10+35510543219541*z^11- 113638922483756*z^12+ 252348200449359*z^13-345027066386175*z^14+ 81356029034411*z^15+ 881468053442834*z^16- 2383892701491756*z^17+3430328807256360*z^18-2918614790283444*z^19+ 1018849254500448*z^20+712292304270640*z^21-1071408562243680*z^22+ 470620280404224*z^23+19240926537600*z^24-78111305206272*z^25+ 11628096196608*z^26+3657667166208*z^27+99851304960*z^28 )/((1-z)^13*(1-2*z)^10*(1-3*z)^7*(1-4*z)^4*(1-5*z))

A213582 Rectangular array: (row n) = b**c, where b(h) = -1 + 2^h, c(h) = n-1+h, n>=1, h>=1, and ** = convolution.

Original entry on oeis.org

1, 5, 2, 16, 9, 3, 42, 27, 13, 4, 99, 68, 38, 17, 5, 219, 156, 94, 49, 21, 6, 466, 339, 213, 120, 60, 25, 7, 968, 713, 459, 270, 146, 71, 29, 8, 1981, 1470, 960, 579, 327, 172, 82, 33, 9, 4017, 2994, 1972, 1207, 699, 384, 198, 93, 37, 10, 8100, 6053, 4007, 2474, 1454, 819, 441, 224, 104, 41, 11
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Comments

Principal diagonal: A213583.
Antidiagonal sums: A156928.
Row 1, (1,3,7,15,31,...)**(1,2,3,4,5,...): A002662.
Row 2, (1,3,7,15,31,...)**(2,3,4,5,6,...)
Row 3, (1,3,7,15,31,...)**(3,4,5,6,7,...)
For a guide to related arrays, see A213500.

Examples

			Northwest corner (the array is read by falling antidiagonals):
1...5....16...42....99....219
2...9....27...68....156...339
3...13...38...94....213...459
4...17...49...120...270...579
5...21...60...146...327...699
6...25...71...172...384...819
		

Crossrefs

Programs

  • GAP
    Flat(List([1..12], n-> List([1..n], k-> 2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2 ))); # G. C. Greubel, Jul 08 2019
  • Magma
    [[2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2: k in [1..n]]: n in [1..12]]; // G. C. Greubel, Jul 08 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= 2^n - 1; c[n_]:= n;
    T[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[T[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[T[n-k+1, k], {n, 12}, {k, n, 1, -1}]] (* A213582 *)
    r[n_]:= Table[T[n, k], {k, 40}]
    Table[T[n, n], {n, 1, 40}] (* A213583 *)
    s[n_]:= Sum[T[i, n+1-i], {i, 1, n}]
    Table[s[n], {n, 1, 50}] (* A156928 *)
    (* Second program *)
    Table[2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2, {n, 12}, {k, n}]//Flatten (* G. C. Greubel, Jul 08 2019 *)
  • PARI
    t(n,k) = 2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2;
    for(n=1,12, for(k=1,n, print1(t(n,k), ", "))) \\ G. C. Greubel, Jul 08 2019
    
  • Sage
    [[2*(k+1)*(2^(n-k+1) -1) -(n-k+1)*(n+k+4)/2 for k in (1..n)] for n in (1..12)] # G. C. Greubel, Jul 08 2019
    

Formula

T(n,k) = 5*T(n,k-1) - 9*T(n,k-2) + 7*T(n,k-3) - 2*T(n,k-4).
G.f. for row n: f(x)/g(x), where f(x) = n - (n-1)*x and g(x) = (1-2*x) *(1-x)^3.
T(n,k) = 2*(n+1)*(2^k - 1) - k*(k + 2*n + 3)/2. - G. C. Greubel, Jul 08 2019

A213583 Principal diagonal of the convolution array A213582.

Original entry on oeis.org

1, 9, 38, 120, 327, 819, 1948, 4482, 10085, 22341, 48930, 106236, 229075, 491175, 1048184, 2227782, 4718097, 9960921, 20970910, 44039520, 92273951, 192937179, 402652308, 838859850, 1744829437, 3623877549, 7516191578, 15569255172, 32212253355, 66571991631
Offset: 1

Views

Author

Clark Kimberling, Jun 19 2012

Keywords

Crossrefs

Programs

  • GAP
    List([1..40], n-> (n+1)*(2^(n+2) -3*n-4)/2); # G. C. Greubel, Jul 08 2019
  • Magma
    [(n+1)*(2^(n+2) -3*n-4)/2: n in [1..40]]; // G. C. Greubel, Jul 08 2019
    
  • Mathematica
    (* First program *)
    b[n_]:= 2^n - 1; c[n_]:= n;
    T[n_, k_]:= Sum[b[k-i] c[n+i], {i, 0, k-1}]
    TableForm[Table[T[n, k], {n, 1, 10}, {k, 1, 10}]]
    Flatten[Table[T[n-k+1, k], {n, 12}, {k, n, 1, -1}]] (* A213582 *)
    r[n_]:= Table[T[n, k], {k, 40}] (* columns of antidiagonal triangle *)
    Table[T[n, n], {n, 1, 40}] (* A213583 *)
    s[n_]:= Sum[T[i, n+1-i], {i, 1, n}]
    Table[s[n], {n, 1, 50}] (* A156928 *)
    (* Second program *)
    LinearRecurrence[{7,-19,25,-16,4},{1,9,38,120,327},40] (* Harvey P. Dale, Apr 06 2013 *)
    Table[(n+1)*(2^(n+2)-3*n-4)/2, {n,40}] (* G. C. Greubel, Jul 08 2019 *)
  • PARI
    Vec(x*(1 + 2*x - 6*x^2) / ((1 - x)^3*(1 - 2*x)^2) + O(x^40)) \\ Colin Barker, Nov 04 2017
    
  • PARI
    vector(40, n, (n+1)*(2^(n+2) -3*n-4)/2) \\ G. C. Greubel, Jul 08 2019
    
  • Sage
    [(n+1)*(2^(n+2) -3*n-4)/2 for n in (1..40)] # G. C. Greubel, Jul 08 2019
    

Formula

a(n) = 7*a(n-1) - 19*a(n-2) + 25*a(n-3) - 16*a(n-4) + 4*a(n-5).
G.f.: x*(1 + 2*x - 6*x^2) / ((1 - x)^3*(1 - 2*x)^2).
a(n) = (n+1)*(2^(n+2) - 3*n -4)/2. - Colin Barker, Nov 04 2017
E.g.f.: (4*(1+2*x)*exp(2*x) - (3*x^2+10*x+4)*exp(x))/2. - G. C. Greubel, Jul 08 2019
Showing 1-7 of 7 results.