A308504 - OEIS

A308504

Square array A(n,k), n >= 1, k >= 0, read by antidiagonals: A(n,k) = Sum_{d|n} d^(n+k).

1, 1, 5, 1, 9, 28, 1, 17, 82, 273, 1, 33, 244, 1057, 3126, 1, 65, 730, 4161, 15626, 47450, 1, 129, 2188, 16513, 78126, 282252, 823544, 1, 257, 6562, 65793, 390626, 1686434, 5764802, 16843009, 1, 513, 19684, 262657, 1953126, 10097892, 40353608, 134480385, 387440173

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OFFSET

1,3

LINKS

Seiichi Manyama, Antidiagonals n = 1..140, flattened

Index entries for sequences related to sigma(n)

FORMULA

L.g.f. of column k: -log(Product_{j>=1} (1 - (j*x)^j)^(j^(k-1))).

a((i-1)*i/2 + j) = sigma_i(j) for 1 <= j <= i.

EXAMPLE

a(4) = a(2*3/2 + 1) = sigma_3(1) = 1.

a(5) = a(2*3/2 + 2) = sigma_3(2) = 1^3 + 2^3 = 9.