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.

A176199 Triangle, read by rows, T(n, k) = f(n,k,q) - f(n,0,q) + 1, where f(n, k, q) = [x^k](p(x,n,q)), p(x, n, q) = (1-x)^(n+1)*Sum_{k >= 0} ( (q*k+1)^n + (q*(k+1)-1)^n )*x^k, and q = 4.

Original entry on oeis.org

1, 1, 1, 1, 35, 1, 1, 329, 329, 1, 1, 2535, 6811, 2535, 1, 1, 18225, 103925, 103925, 18225, 1, 1, 127435, 1384685, 2868895, 1384685, 127435, 1, 1, 881977, 17115873, 64568761, 64568761, 17115873, 881977, 1, 1, 6089807, 202236439, 1283008495, 2302094507, 1283008495, 202236439, 6089807, 1
Offset: 0

Views

Author

Roger L. Bagula, Apr 11 2010

Keywords

Examples

			Triangle begins as:
  1;
  1,      1;
  1,     35,        1;
  1,    329,      329,        1;
  1,   2535,     6811,     2535,        1;
  1,  18225,   103925,   103925,    18225,        1;
  1, 127435,  1384685,  2868895,  1384685,   127435,      1;
  1, 881977, 17115873, 64568761, 64568761, 17115873, 881977,     1;
		

Crossrefs

Related triangles dependent on q: A008518 (q=1), A176198 (q=2), A174599 (q=3), this sequence (q=4).

Programs

  • Magma
    m:=13;
    R:=PowerSeriesRing(Integers(), m+2);
    p:= func< x,n,q | (1-x)^(n+1)*(&+[((q*j+1)^n + (q*(j+1)-1)^n)*x^j: j in [0..m+2]]) >;
    f:= func< n,k,q | Coefficient(R!( p(x,n,q) ), k) >;
    T:= func< n,k,q | f(n,k,q) - f(n,0,q) + 1 >; // T = A176199
    [T(n,k,4): k in [0..n], n in [0..m]]; // G. C. Greubel, Jun 18 2024
    
  • Mathematica
    m:=13;
    p[x_,n_,q_]:= (1-x)^(n+1)*Sum[((q*j+1)^n+(q*(j+1)-1)^n)*x^j, {j,0,m+ 2}];
    f[n_,k_,q_]:= Coefficient[Series[p[x,n,q], {x,0,m+2}], x, k];
    T[n_,k_,q_]:= f[n,k,q] - f[n,0,q] + 1;
    Table[T[n,k,4], {n,0,m}, {k,0,n}]//Flatten
  • SageMath
    m=13
    def p(x,n,q): return (1-x)^(n+1)*sum(((q*j+1)^n + (q*(j+1)-1)^n)*x^j for j in range(m+3))
    def f(n,k,q): return ( p(x,n,q) ).series(x, n+1).list()[k]
    def T(n,k,q): return f(n,k,q) - f(n,0,q) + 1 # T = A176199
    flatten([[T(n,k,4) for k in range(n+1)] for n in (0..m)]) # G. C. Greubel, Jun 18 2024

Formula

T(n, k) = f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = (1-x)^(n+1) * Sum_{k >= 0} ( (q*k + 1)^n + (q*(k+1) - 1)^n )*x^k, and q = 4.
T(n, k) f(n, k, q) - f(n, 0, q) + 1, where f(n, k, q) = [x^k]( p(x, n, q) ), p(x, n, q) = q^n * (1-x)^(n+1) * ( LerchPhi(x, -n, 1/q) + LerchPhi(x, -n, (q-1)/q) ), and q = 4.
T(n, n-k) = T(n, k).

Extensions

Edited by G. C. Greubel, Jun 18 2024