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.

A188474 A generalized Deutsch triangle.

Original entry on oeis.org

1, 1, 1, 1, 5, 1, 1, 10, 10, 1, 1, 16, 40, 16, 1, 1, 23, 102, 102, 23, 1, 1, 31, 209, 393, 209, 31, 1, 1, 40, 376, 1122, 1122, 376, 40, 1, 1, 50, 620, 2656, 4296, 2656, 620, 50, 1, 1, 61, 960, 5536, 13100, 13100, 5536, 960, 61, 1, 1, 73, 1417, 10522, 34036, 50180, 34036, 10522, 1417, 73, 1
Offset: 0

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Author

Paul Barry, Apr 01 2011

Keywords

Comments

Member r=2 of the family of "Pascal-like" triangles with T(n,k)=sum{j=0..n-k+1, (j/(n+2-j))*C(n+2-j,n-k+1)*C(n+2-j,k+1)*r^(j-1)}.
The Deutsch triangle A100754 corresponds to r=1.
Row sums are A137398(n+1) (conjecture). Diagonal sums are A188476.

Examples

			Triangle begins
1,
1, 1,
1, 5, 1,
1, 10, 10, 1,
1, 16, 40, 16, 1,
1, 23, 102, 102, 23, 1,
1, 31, 209, 393, 209, 31, 1,
1, 40, 376, 1122, 1122, 376, 40, 1,
1, 50, 620, 2656, 4296, 2656, 620, 50, 1,
1, 61, 960, 5536, 13100, 13100, 5536, 960, 61, 1,
1, 73, 1417, 10522, 34036, 50180, 34036, 10522, 1417, 73, 1
		

Formula

T(n,k)=sum{j=0..n-k+1, (j/(n+2-j))*C(n+2-j,n-k+1)*C(n+2-j,k+1)*2^(j-1)}.