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 1-8 of 8 results.

A047848 Array A read by diagonals; n-th difference of (A(k,n), A(k,n-1),..., A(k,0)) is (k+2)^(n-1), for n=1,2,3,...; k=0,1,2,...

Original entry on oeis.org

1, 2, 1, 5, 2, 1, 14, 6, 2, 1, 41, 22, 7, 2, 1, 122, 86, 32, 8, 2, 1, 365, 342, 157, 44, 9, 2, 1, 1094, 1366, 782, 260, 58, 10, 2, 1, 3281, 5462, 3907, 1556, 401, 74, 11, 2, 1, 9842, 21846, 19532, 9332, 2802, 586, 92, 12, 2, 1, 29525, 87382, 97657, 55988, 19609, 4682, 821, 112, 13, 2, 1
Offset: 0

Views

Author

Keywords

Examples

			Array, A(n, k), begins as:
  1, 2,  5,  14,   41, ... = A007051.
  1, 2,  6,  22,   86, ... = A047849.
  1, 2,  7,  32,  157, ... = A047850.
  1, 2,  8,  44,  260, ... = A047851.
  1, 2,  9,  58,  401, ... = A047852.
  1, 2, 10,  74,  586, ... = A047853.
  1, 2, 11,  92,  821, ... = A047854.
  1, 2, 12, 112, 1112, ... = A047855.
  1, 2, 13, 134, 1465, ... = A047856.
  1, 2, 14, 158, 1886, ... = A196791.
  1, 2, 15, 184, 2381, ... = A196792.
Downward antidiagonals, T(n, k), begins as:
      1;
      2,     1;
      5,     2,     1;
     14,     6,     2,     1;
     41,    22,     7,     2,     1;
    122,    86,    32,     8,     2,    1;
    365,   342,   157,    44,     9,    2,   1;
   1094,  1366,   782,   260,    58,   10,   2,   1;
   3281,  5462,  3907,  1556,   401,   74,  11,   2,  1;
   9842, 21846, 19532,  9332,  2802,  586,  92,  12,  2, 1;
  29525, 87382, 97657, 55988, 19609, 4682, 821, 112, 13, 2, 1;
		

Crossrefs

Cf. A047857 (row sums), A196793 (main diagonal).

Programs

  • Magma
    A:= func< n,k | ((n+3)^k +n+1)/(n+2) >; // array A047848
    [A(k,n-k): k in [0..n], n in [0..12]]; // G. C. Greubel, Jan 11 2025
    
  • Mathematica
    A[n_, k_]:= ((n+3)^k +n+1)/(n+2);
    A047848[n_, k_]:= A[k,n-k];
    Table[A047848[n,k], {n,0,12}, {k,0,n}]//Flatten (* G. C. Greubel, Jan 11 2025 *)
  • Python
    def A(n,k): return (pow(n+3,k) +n+1)//(n+2) # array A047848
    print(flatten([[A(k,n-k) for k in range(n+1)] for n in range(13)])) # G. C. Greubel, Jan 11 2025

Formula

A(n, k) = ((n+3)^k + n + 1)/(n+2). - Ralf Stephan, Feb 14 2004
From G. C. Greubel, Jan 11 2025: (Start)
T(n, k) = ((k+3)^(n-k) + k + 1)/(k+2) (antidiagonal triangle).
T(n, n) = A196793(n).
Sum_{k=0..n} T(n, k) = A047857(n). (End)

A196791 a(n) = A047848(9, n).

Original entry on oeis.org

1, 2, 14, 158, 1886, 22622, 271454, 3257438, 39089246, 469070942, 5628851294, 67546215518, 810554586206, 9726655034462, 116719860413534, 1400638324962398, 16807659899548766, 201691918794585182, 2420303025535022174, 29043636306420266078, 348523635677043192926
Offset: 0

Views

Author

Vincenzo Librandi, Oct 11 2011

Keywords

Crossrefs

Cf. A001021 (first differences).

Programs

  • Magma
    [(12^n+10)/11: n in [0..20]];
    
  • Mathematica
    LinearRecurrence[{13,-12},{1,2},30] (* Harvey P. Dale, Sep 07 2015 *)
    (12^Range[0,40] +10)/11 (* G. C. Greubel, Jan 17 2025 *)
  • Python
    def A196791(n): return (pow(12, n) + 10)//11
    print([A196791(n) for n in range(41)]) # G. C. Greubel, Jan 17 2025

Formula

a(n) = (12^n + 10)/11.
a(n) = 12*a(n-1) - 10, with a(0) = 1.
G.f.: (1-11*x)/((1-x)*(1-12*x)). - Bruno Berselli, Oct 11 2011
From Elmo R. Oliveira, Aug 30 2024: (Start)
E.g.f.: exp(x)*(exp(11*x) + 10)/11.
a(n) = 13*a(n-1) - 12*a(n-2) for n > 1. (End)

A196792 a(n) = A047848(10, n).

Original entry on oeis.org

1, 2, 15, 184, 2381, 30942, 402235, 5229044, 67977561, 883708282, 11488207655, 149346699504, 1941507093541, 25239592216022, 328114698808275, 4265491084507564, 55451384098598321, 720867993281778162, 9371283912663116095, 121826690864620509224, 1583746981240066619901
Offset: 0

Views

Author

Vincenzo Librandi, Oct 11 2011

Keywords

Crossrefs

Cf. A001022 (first differences).

Programs

  • Magma
    [(13^n+11)/12: n in [0..20]];
    
  • Mathematica
    (13^Range[0,40] +11)/12 (* G. C. Greubel, Jan 17 2025 *)
  • Python
    def A196792(n): return (pow(13, n) + 11)//12
    print([A196792(n) for n in range(41)]) # G. C. Greubel, Jan 17 2025

Formula

a(n) = (13^n + 11)/12.
a(n) = 13*a(n-1) - 11, with a(0) = 1.
G.f.: (1-12*x)/((1-x)*(1-13*x)). - Bruno Berselli, Oct 11 2011
From Elmo R. Oliveira, Aug 30 2024: (Start)
E.g.f.: exp(x)*(exp(12*x) + 11)/12.
a(n) = 14*a(n-1) - 13*a(n-2) for n > 1. (End)

A196793 a(n) = A047848(n, n).

Original entry on oeis.org

1, 2, 7, 44, 401, 4682, 66431, 1111112, 21435889, 469070942, 11488207655, 311505013052, 9267595563617, 300239975158034, 10523614159962559, 396861212733968144, 16024522975978953761, 689852631578947368422, 31544039619835776489479
Offset: 0

Views

Author

Vincenzo Librandi, Oct 11 2011

Keywords

Crossrefs

Programs

Formula

a(n) = ((n+3)^n + n + 1)/(n+2).

A062508 a(n) = 3^(2n)+7.

Original entry on oeis.org

8, 16, 88, 736, 6568, 59056, 531448, 4782976, 43046728, 387420496, 3486784408, 31381059616, 282429536488, 2541865828336, 22876792454968, 205891132094656, 1853020188851848, 16677181699666576, 150094635296999128
Offset: 0

Views

Author

Jason Earls, Jun 24 2001

Keywords

References

  • D. M. Burton, Elementary Number Theory, Allyn and Bacon, Inc. Boston, MA, 1976, pp. 29.

Crossrefs

Cf. A047854.

Programs

Formula

a(0)=8, a(1)=16, a(n)=10*a(n-1)-9*a(n-2). - Harvey P. Dale, May 13 2012

A377735 Cogrowth sequence of the 16-element group Q8 X C2 = .

Original entry on oeis.org

1, 1, 7, 103, 829, 7261, 66595, 598627, 5377849, 48426745, 435876607, 3922582687, 35303534581, 317733991381, 2859598948507, 25736384863003, 231627537879409, 2084647743751921, 18761829221081335, 168856464809568727, 1519708183900618669, 13677373637498037325
Offset: 0

Views

Author

Sean A. Irvine, Nov 10 2024

Keywords

Comments

Gives the even terms, all the odd terms are 0.

Crossrefs

Cf. A047854 (D4 X C2), A377840 (C8 X C2), A071930 (Q8).

Formula

G.f.: (27*x^3+3*x^2+7*x-1) / ((1-x) * (9*x-1) * (9*x^2+2*x+1)).

A377943 Cogrowth sequence of the 16-element Pauli group C4 o D4 = .

Original entry on oeis.org

1, 1, 11, 91, 821, 7381, 66431, 597871, 5380841, 48427561, 435848051, 3922632451, 35303692061, 317733228541, 2859599056871, 25736391511831, 231627523606481, 2084647712458321, 18761829412124891, 168856464709124011, 1519708182382116101, 13677373641439044901
Offset: 0

Views

Author

Sean A. Irvine, Nov 11 2024

Keywords

Comments

Gives the even terms, all the odd terms are 0.

Crossrefs

Cf. A070775 (C4 X C4), A377855 (C4:C4), A047854 (D4 X C2).

Formula

G.f.: (x^2-8*x+1) / ((x-1) * (9*x-1) * (x+1)).

A166124 Triangle, read by rows, given by [0,1/2,1/2,0,0,0,0,0,0,0,...] DELTA [2,-1,0,0,0,0,0,0,0,0,...] where DELTA is the operator defined in A084938.

Original entry on oeis.org

1, 0, 2, 0, 1, 2, 0, 1, 1, 2, 0, 1, 1, 1, 2, 0, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 2
Offset: 0

Views

Author

Philippe Deléham, Oct 07 2009

Keywords

Examples

			Triangle begins :
1 ;
0,2 ;
0,1,2 ;
0,1,1,2 ;
0,1,1,1,2 ;
0,1,1,1,1,2 ;
0,1,1,1,1,1,2 ; ...
		

Formula

Sum_{k, 0<=k<=n} T(n,k)*x^(n-k)= A166122(n), A166114(n), A084222(n), A084247(n), A000034(n), A040000(n), A000027(n+1), A000079(n), A007051(n), A047849(n), A047850(n), A047851(n), A047852(n), A047853(n), A047854(n), A047855(n), A047856(n) for x= -5,-4,-3,-2,-1,0,1,2,3,4,5,6,7,8,9,10,11 respectively.
Sum_{k, 0<=k<=n} T(n,k)*x^k= A000007(n), A000027(n+1), A033484(n), A134931(n), A083597(n) for x= 0,1,2,3,4 respectively.
T(n,k)= A166065(n,k)/2^(n-k).
G.f.: (1-x+x*y)/(1-x-x*y+x^2*y). - Philippe Deléham, Nov 09 2013
T(n,k) = T(n-1,k) + T(n-1,k-1) - T(n-2,k-1), T(0,0) = 1, T(1,0) = 0, T(1,1) = 2, T(n,k) = 0 if k<0 or if k>n. - Philippe Deléham, Nov 09 2013
Showing 1-8 of 8 results.