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.

A187913 Generalized Riordan array based on the Fine's numbers A000957.

Original entry on oeis.org

1, 0, 1, 1, 1, 1, 2, 4, 1, 1, 6, 10, 5, 2, 1, 18, 32, 13, 9, 2, 1, 57, 100, 44, 28, 10, 3, 1, 186, 329, 142, 100, 32, 15, 3, 1, 622, 1101, 480, 344, 119, 55, 16, 4, 1, 2120, 3761, 1640, 1214, 420, 216, 60, 22, 4, 1, 7338, 13035, 5698, 4300, 1517, 810, 243, 92, 23, 5, 1
Offset: 0

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Author

Paul Barry, Mar 15 2011

Keywords

Comments

First column is the Fine's numbers A000957. Row sums are A000958. Inverse binomial transform of A187914.

Examples

			Triangle begins
1,
0, 1,
1, 1, 1,
2, 4, 1, 1,
6, 10, 5, 2, 1,
18, 32, 13, 9, 2, 1,
57, 100, 44, 28, 10, 3, 1,
186, 329, 142, 100, 32, 15, 3, 1,
622, 1101, 480, 344, 119, 55, 16, 4, 1,
2120, 3761, 1640, 1214, 420, 216, 60, 22, 4, 1,
7338, 13035, 5698, 4300, 1517, 810, 243, 92, 23, 5, 1
Production matrix is
0, 1,
1, 1, 1,
1, 2, 0, 1,
1, 2, 1, 1, 1,
1, 2, 1, 2, 0, 1,
1, 2, 1, 2, 1, 1, 1,
1, 2, 1, 2, 1, 2, 0, 1,
1, 2, 1, 2, 1, 2, 1, 1, 1,
1, 2, 1, 2, 1, 2, 1, 2, 0, 1
Thus
57=1.0+0.18+1.32+1.13+1.9+1.2+1.1;
100=1.18+1.32+2.13+2.9+2.2+2.1;
44=1.32+0.13+1.9+1.2+1.1
		

Formula

Let g(x)=(1+2x-sqrt(1-4x))/(2x(2+x)) be the g.f. of the Fine's numbers A000957. Then column k has
g.f. x^k*g(x)^(k+1)/(1-xg(x)-x^2g(x)^2)^floor((k+1)/2).