A286656 Square array A(n,k), n>=0, k>=1, read by antidiagonals, where column k is the expansion of Product_{j>=1} (1 - x^j)/(1 - x^(k*j)).

1, 1, 0, 1, -1, 0, 1, -1, 0, 0, 1, -1, -1, -1, 0, 1, -1, -1, 1, 1, 0, 1, -1, -1, 0, -1, -1, 0, 1, -1, -1, 0, 1, 0, 1, 0, 1, -1, -1, 0, 0, 0, 2, -1, 0, 1, -1, -1, 0, 0, 2, -1, -1, 2, 0, 1, -1, -1, 0, 0, 1, -1, 1, -1, -2, 0, 1, -1, -1, 0, 0, 1, 1, 0, 2, 3, 2, 0, 1

Offset: 0

Author

Seiichi Manyama, May 14 2017

Keywords

• sign
• tabl

Examples

			Square array begins:
   1,  1,  1,  1,  1, ...
   0, -1, -1, -1, -1, ...
   0,  0, -1, -1, -1, ...
   0, -1,  1,  0,  0, ...
   0,  1, -1,  1,  0, ...
		

Crossrefs

Columns k=1-5 give: A000007, A081362, A137569, A082303, A145466.

Main diagonal gives A010815.

Cf. A286653.

Formula

G.f. of column k: Product_{j>=1} (1 - x^j)/(1 - x^(k*j)).