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.

A135299 Pascal's triangle, but the last element of the row is the sum of all the previous terms.

Original entry on oeis.org

1, 1, 2, 1, 3, 8, 1, 4, 11, 32, 1, 5, 15, 43, 128, 1, 6, 20, 58, 171, 512, 1, 7, 26, 78, 229, 683, 2048, 1, 8, 33, 104, 307, 912, 2731, 8192, 1, 9, 41, 137, 411, 1219, 3643, 10923, 32768, 1, 10, 50, 178, 548, 1630, 4862, 14566, 43691, 131072
Offset: 0

Views

Author

Jose Ramon Real, Dec 04 2007

Keywords

Examples

			T(2,1) = T(1,0) + T(1,1) = 1 + 2 = 3;
T(2,2) = T(0,0) + T(1,0) + T(1,1) + T(2,0) + T(2,1) = 1 + 1 + 2 + 1 + 3 = 8.
From _G. C. Greubel_, Oct 09 2016: (Start)
The triangle is:
  1;
  1, 2;
  1, 3,  8;
  1, 4, 11, 32;
  1, 5, 15, 43, 128;
  1, 6, 20, 58, 171, 512;
  ... (End)
		

Crossrefs

Programs

  • Mathematica
    T[0, 0] := 1; T[n_, 0] := 1; T[n_, k_] := T[n - 1, k] + T[n - 1, k - 1]; T[n_, n_] := 2^(2*n - 1); Table[T[n, k], {n, 0, 5}, {k, 0, n}] (* G. C. Greubel, Oct 09 2016 *)

Formula

T(0,0) = 1;
T(n,0) = 1;
T(n,k) = T(n-1, k-1) + T(n-1, k) if k < n;
T(n,n) = (Sum_{j=0..n-1} Sum_{i=0..j} T(j,i)) + Sum_{i=0..n-1} T(n,i) [i.e., sum of all earlier terms of the triangle].
T(n,n) = (4^n)/2 for n > 0;
T(n,n) = 2*Sum_{i=0..n-1} T(n,i).