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URL: https://oeis.org/A353924

⇱ A353924 - OEIS

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A353924
Product_{n>=1} (1 + a(n)*x^n) = 1 + Sum_{n>=1} sigma(n)*x^n, where sigma = A000203.
4
1, 3, 1, 6, -3, -6, -1, 40, 3, -50, -1, 73, 3, -315, 1, 1953, 1, -2117, 7, 5625, -13, -16116, 27, 33728, 29, -122648, 3, 351244, -25, -913057, -81, 5447169, 89, -7596153, 637, 22521844, -275, -61171056, -263, 177290760, -453, -487655426, -583, 1523295127, 8121, -4093188035
OFFSET
1,2
FORMULA
Product_{n>=1} (1 + a(n)*x^n) = 1 + Sum_{n>=1} x^n / (1 - x^n)^2.
MATHEMATICA
A[m_, n_] := A[m, n] = Which[m == 1, DivisorSigma[1, n], m > n >= 1, 0, True, A[m - 1, n] - A[m - 1, m - 1] A[m, n - m + 1]]; a[n_] := A[n, n]; a /@ Range[1, 46]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, May 11 2022
STATUS
approved