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.

A154109 Convolution triangle by rows, A004736 * (A154108 * 0^(n-k)); row sums = Bell numbers.

Original entry on oeis.org

1, 2, 0, 3, 0, 2, 4, 0, 4, 7, 5, 0, 6, 14, 27, 6, 0, 8, 21, 54, 114, 7, 0, 10, 28, 81, 228, 523, 8, 0, 12, 35, 108, 342, 1046, 2589, 9, 0, 14, 42, 135, 456, 1569, 5178, 13744, 10, 0, 16, 49, 162, 570, 2092, 7767, 27488, 77821
Offset: 1

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Author

Gary W. Adamson, Jan 04 2009

Keywords

Comments

Row sums = Bell numbers, A000110 starting (1, 2, 5, 15, 52, 203, 877,...).

Examples

			First few rows of the triangle =
1;
2, 0;
3, 0, 2;
4, 0, 4, 7;
5, 0, 6, 14, 27;
6, 0, 8, 21, 54, 114;
7, 0, 10, 28, 81, 228, 523;
8, 0, 12, 35, 108, 342, 1046, 2589;
9, 0, 14, 42, 135, 456, 1569, 5178, 13744;
10, 0, 16, 49, 162, 570, 2092, 7767, 27488, 77821;
...
Row 5 = (5, 0, 6, 14, 27), sum = A000110(5) = 52 = termwise products of
(5, 4, 3, 2, 1) and (1, 0, 2, 7, 27).
		

Crossrefs

Formula

A004736 * (A154108 * 0^(n-k)); where A004736 = an infinite lower triangular
matrix with (1,2,3,...) in every column and (A154108 * 0^(n-k)) = a matrix
with A154108 (1, 0, 2, 7, 27, 114, 523, 2589...) as the main diagonal
and the rest zeros.