A204851 Triangle by rows relating to A005773.
1, 1, 1, 2, 2, 1, 5, 5, 2, 1, 13, 13, 6, 2, 1, 35, 35, 16, 7, 2, 1, 96, 96, 45, 19, 8, 2, 1, 267, 267, 126, 56, 22, 9, 2, 1, 750, 750, 357, 160, 68, 25, 10, 2, 1, 2123, 2123, 1016, 463, 198, 81, 28, 11, 2, 1, 6046, 6046, 2907, 1337, 586, 240, 95, 31, 12, 2, 1
Offset: 0
Examples
First few rows of the triangle = 1; 1, 1; 2, 2, 1; 5, 5, 2, 1; 13, 13, 6, 2, 1; 35, 35, 16, 7, 2, 1; 96, 96, 45, 19, 8, 2, 1; 267, 267, 126, 56, 22, 9, 2, 1; 750, 750, 357, 160, 68, 25, 10, 2, 1; 2123, 2123, 1016, 463, 198, 81, 28, 11, 2, 1; 6046, 6046, 2907, 1337, 586, 240, 95, 31, 12, 2, 1; ... Row 3 = (5, 5, 2, 1) since the top row of M^3 = [5, 5, 2, 1, 0, 0, 0,...]
Crossrefs
Cf. A005773
Formula
n-th row of the triangle is the top row of M^n, deleting the zeros; where M = the infinite square production matrix:
1, 1, 0, 0, 0, 0, 0,...
1, 1, 1, 0, 0, 0, 0,...
1, 1, 0, 1, 0, 0, 0,...
1, 1, 1, 0, 1, 0, 0,...
1, 1, 1, 1, 0, 1, 0,...
1, 1, 1, 1, 1, 0, 1,...
1, 1, 1, 1, 1, 1, 0,...
...
Comments