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.

A194583 Triangle T(n,k) with T(n,0)=1 and T(n,k) = (2^(n+1)-2^k)*T(n,k-1) + T(n+1,k-1) otherwise.

Original entry on oeis.org

1, 1, 3, 1, 7, 43, 1, 15, 211, 2619, 1, 31, 931, 26251, 654811, 1, 63, 3907, 234795, 13255291, 662827803, 1, 127, 16003, 1985131, 238658491, 26961325147, 2699483026843, 1, 255, 64771, 16323819, 4050110011, 973958217435, 220115609012251, 44102911693372059, 1, 511, 260611, 132393451, 66733574971, 33115631264731, 15928113739803931, 7200501591899676571, 2886238576935227688091
Offset: 0

Views

Author

R. J. Mathar, Aug 29 2011

Keywords

Examples

			The triangle starts in row n=0 as
  1;
  1,  3;
  1,  7,  43;
  1, 15, 211,  2619;
  1, 31, 931, 26251, 654811;
		

Programs

  • Maple
    A194583 := proc(n,k) option remember; if n=0 or k=0 then 1; elif k> n then
    return procname(k,n); else (2^(n+1)-2^k)*procname(n,k-1)+procname(n+1,k-1) ; end if;
    end proc:
  • Mathematica
    t[, 0] = 1; t[n, k_] := t[n, k] = (2^(n+1)-2^k)*t[n, k-1]+t[n+1, k-1]; Table[t[n, k], {n, 0, 8}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 10 2014 *)

Formula

T(n,1) = A000225(n+1).
T(n,2) = (2^(n+1)-4)*(2^(n+1)-1) + 2^(n+2) - 1.
T(n,k) = -Sum_{j=1..k+1} A158474(k+1,j)*T(n-j,k) assuming the symmetric extension T(n,k) = T(k,n).