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 1-4 of 4 results.

A165883 Irregular triangle T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (1-x)^(2*n+3)*( Sum_{j >= 0} (2*j+ 1)^n*x^j )*( Sum_{j >= 0} j^(n+1)*x^j ), read by rows.

Original entry on oeis.org

1, 1, 2, 1, 1, 10, 26, 10, 1, 1, 34, 287, 508, 287, 34, 1, 1, 102, 2272, 11098, 19134, 11098, 2272, 102, 1, 1, 294, 15493, 169432, 675706, 1042948, 675706, 169432, 15493, 294, 1, 1, 842, 98374, 2151026, 17138559, 55643460, 82178676, 55643460, 17138559, 2151026, 98374, 842, 1
Offset: 0

Views

Author

Roger L. Bagula, Sep 29 2009

Keywords

Examples

			Irregular triangle begins as:
  1;
  1,   2,     1;
  1,  10,    26,     10,      1;
  1,  34,   287,    508,    287,      34,      1;
  1, 102,  2272,  11098,  19134,   11098,   2272,    102,     1;
  1, 294, 15493, 169432, 675706, 1042948, 675706, 169432, 15493, 294, 1;
		

Crossrefs

Programs

  • Mathematica
    p[n_, x_]:= p[n, x]= (1/x)*(1-x)^(2*n+3)*Sum[(2*k+1)^n*x^k, {k,0,Infinity}]*Sum[k^(n+1)*x^k, {k,0,Infinity}];
    Table[CoefficientList[p[n, x], x], {n,0,10}]//Flatten (* modified by G. C. Greubel, Mar 08 2022 *)
  • Sage
    def p(n,x): return (1/x)*(1-x)^(2*n+3)*sum( (2*j+1)^n*x^j for j in (0..2*n+3) )*sum( j^(n+1)*x^j for j in (0..2*n+3) )
    def T(n,k): return ( p(n,x) ).series(x, 2*n+1).list()[k]
    flatten([[T(n,k) for k in (0..2*n)] for n in (0..12)]) # G. C. Greubel, Mar 08 2022

Formula

T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (1-x)^(2*n+3)*( Sum_{j >= 0} (2*j+ 1)^n*x^j )*( Sum_{j >= 0} j^(n+1)*x^j ).
T(n, k) = [x^k]( p(n, x) ), where p(n, x) = 2^n*(1-x)^(2*n+3)*LerchPhi(x, -n, 1/2)*PolyLog(-n-1, x)/x.
T(n, n-k) = T(n, k). - G. C. Greubel, Mar 08 2022

Extensions

Edited by G. C. Greubel, Mar 08 2022

A165890 Irregular triangle T(n, k) = [x^k]( p(n, x) ), where p(n, x) = ( (1-x)^(n+1) * Sum_{k >= 0} (2*k+1)^(n-1)*x^k )^2, read by rows.

Original entry on oeis.org

1, 1, -2, 1, 1, 0, -2, 0, 1, 1, 10, 15, -52, 15, 10, 1, 1, 44, 484, -44, -970, -44, 484, 44, 1, 1, 150, 5933, 22792, 466, -58684, 466, 22792, 5933, 150, 1, 1, 472, 58586, 682040, 2085135, -682512, -4287444, -682512, 2085135, 682040, 58586, 472, 1
Offset: 0

Views

Author

Roger L. Bagula, Sep 29 2009

Keywords

Examples

			Irregular triangle begins as:
  1;
  1,  -2,    1;
  1,   0,   -2,     0,    1;
  1,  10,   15,   -52,   15,     10,   1;
  1,  44,  484,   -44, -970,    -44, 484,    44,    1;
  1, 150, 5933, 22792,  466, -58684, 466, 22792, 5933, 150, 1;
		

Crossrefs

Cf. A000007 (row sums), A158782, A165883, A165889, A165891.

Programs

  • Mathematica
    p[n_, x_]:= p[n, x]= If[n==0, 1, (2^(n-1)*(1-x)^(n+1)*LerchPhi[x, -n+1, 1/2])^2];
    Table[CoefficientList[p[n, x], x], {n,0,12}]//Flatten (* modified by G. C. Greubel, Mar 09 2022 *)
  • Sage
    def p(n,x): return (1-x)^(2*n+2)*sum( (2*j+1)^(n-1)*x^j for j in (0..2*n+2) )^2
    def T(n,k): return ( p(n,x) ).series(x, 2*n+2).list()[k]
    flatten([[T(n,k) for k in (0..2*n)] for n in (0..12)]) # G. C. Greubel, Mar 09 2022

Formula

T(n, k) = [x^k]( p(n, x) ), where p(n, x) = ( (1-x)^(n+1)*Sum_{k >= 0} (2*k+1)^(n-1)*x^k )^2.
T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (2^(n-1)*(1-x)^(n+2)*LerchPhi(x, -n+1, 1/2))^2.
Sum_{k=0..n} T(n, k) = 0^n.
T(n, n-k) = T(n, k). - G. C. Greubel, Mar 09 2022

Extensions

Edited by G. C. Greubel, Mar 09 2022

A165891 Irregular triangle T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (1/x)*(1-x)^n*(1+x)^(n+2)*( Sum_{j >= 0} j^(n+1)*x^j ), read by rows.

Original entry on oeis.org

1, 1, 2, 1, 1, 6, 10, 6, 1, 1, 14, 47, 68, 47, 14, 1, 1, 30, 176, 450, 606, 450, 176, 30, 1, 1, 62, 597, 2392, 5162, 6612, 5162, 2392, 597, 62, 1, 1, 126, 1926, 11382, 35967, 69132, 85492, 69132, 35967, 11382, 1926, 126, 1, 1, 254, 6043, 50892, 223785, 600546, 1060411, 1277096, 1060411, 600546, 223785, 50892, 6043, 254, 1
Offset: 0

Views

Author

Roger L. Bagula, Sep 29 2009

Keywords

Examples

			Irregular triangle begins as:
  1;
  1,   2,    1;
  1,   6,   10,     6,     1;
  1,  14,   47,    68,    47,    14,     1;
  1,  30,  176,   450,   606,   450,   176,    30,     1;
  1,  62,  597,  2392,  5162,  6612,  5162,  2392,   597,    62,    1;
  1, 126, 1926, 11382, 35967, 69132, 85492, 69132, 35967, 11382, 1926, 126, 1;
		

Crossrefs

Programs

  • Mathematica
    p[n_, x_]:= p[n, x]= (1/x)*(1+x)^n*(1-x)^(n+2)*PolyLog[-n-1, x];
    Table[CoefficientList[p[n, x], x], {n,0,12}]//Flatten (* modified by G. C. Greubel, Mar 09 2022 *)
  • Sage
    def p(n,x): return (1/x)*(1+x)^n*(1-x)^(n+2)*polylog(-n-1, x)
    def T(n,k): return ( p(n,x) ).series(x, 2*n+1).list()[k]
    flatten([[T(n,k) for k in (0..2*n)] for n in (0..12)]) # G. C. Greubel, Mar 09 2022

Formula

T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (1/x)*(1-x)^n*(1+x)^(n+2)*( Sum_{j >= 0} j^(n+1)*x^j ).
T(n, k) = [x^k]( p(n, x) ), where p(n, x) = (1/x)*(1+x)^n * (1-x)^(n+2)*PolyLog(-n-1, x).
T(n, n-k) = T(n, k). - G. C. Greubel, Mar 09 2022

Extensions

Edited by G. C. Greubel, Mar 09 2022

A382232 Irregular triangle read by rows: T(n,k) = [x^k] (1+x) * A_n(x)^2, where A_n(x) is the n-th Eulerian polynomial.

Original entry on oeis.org

1, 1, 1, 1, 1, 3, 3, 1, 1, 9, 26, 26, 9, 1, 1, 23, 165, 387, 387, 165, 23, 1, 1, 53, 860, 4292, 9194, 9194, 4292, 860, 53, 1, 1, 115, 3967, 38885, 160778, 314654, 314654, 160778, 38885, 3967, 115, 1, 1, 241, 17022, 307454, 2291375, 8041695, 14743812, 14743812, 8041695, 2291375, 307454, 17022, 241, 1
Offset: 0

Views

Author

Seiichi Manyama, Mar 19 2025

Keywords

Examples

			Irregular triangle begins:
  1,  1;
  1,  1;
  1,  3,   3,    1;
  1,  9,  26,   26,    9,    1;
  1, 23, 165,  387,  387,  165,   23,   1;
  1, 53, 860, 4292, 9194, 9194, 4292, 860, 53, 1;
  ...
		

Crossrefs

Row sums give A048617.

Programs

  • PARI
    a(n) = sum(k=0, n, k!*stirling(n, k, 2)*(x-1)^(n-k));
    T(n, k) = polcoef((1+x)*a(n)^2, k);
    for(n=0, 7, for(k=0, 2*(n+0^n)-1, print1(T(n, k), ", ")));

Formula

T(n,k) = T(n,2*n-1-k) for n > 0.
Showing 1-4 of 4 results.