OFFSET
0,6
LINKS
Seiichi Manyama, Antidiagonals n = 0..139, flattened
FORMULA
G.f. of column k: Product_{i>=1, j>=1} 1/(1 - x^(i*j))^(j^k).
G.f. of column k: exp(Sum_{j>=1} sigma_(k+1)(j)*x^j/(j*(1 - x^j))).
EXAMPLE
Square array begins:
1, 1, 1, 1, 1, 1, ...
1, 1, 1, 1, 1, 1, ...
3, 4, 6, 10, 18, 34, ...
5, 8, 16, 38, 100, 278, ...
11, 21, 52, 156, 526, 1896, ...
17, 39, 128, 534, 2546, 13074, ...
MATHEMATICA
Table[Function[k, SeriesCoefficient[Product[1/(1 - x^j)^DivisorSigma[k, j], {j, 1, n}], {x, 0, n}]][i - n], {i, 0, 10}, {n, 0, i}] // Flatten
Table[Function[k, SeriesCoefficient[Exp[Sum[DivisorSigma[k + 1, j] x^j/(j (1 - x^j)), {j, 1, n}]], {x, 0, n}]][i - n], {i, 0, 10}, {n, 0, i}] // Flatten
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Ilya Gutkovskiy, Nov 20 2018
STATUS
approved