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A320255
a(n) = n! * [x^n] log(1 + exp(x)*(x + (n/2 - 1)*x^2)).
1
0, 1, 1, -1, -26, 39, 3666, -7400, -1488416, 3802113, 1322570530, -4095154284, -2187371499312, 7964242253473, 6052757424558586, -25343867475914910, -25988018018090461664, 123032891453320498449, 163684285184147641156098, -864557405968781387651984, -1448111703094244548802632160
OFFSET
0,5
COMMENTS
For n > 2, a(n) is the n-th term of the logarithmic transform of n-gonal numbers.
MATHEMATICA
Table[n! SeriesCoefficient[Log[1 + Exp[x] (x + (n/2 - 1) x^2)], {x, 0, n}], {n, 0, 20}]
CROSSREFS
KEYWORD
sign
AUTHOR
Ilya Gutkovskiy, Oct 08 2018
STATUS
approved