The On-Line Encyclopedia of Integer Sequences (OEIS)

Revision History for A320255 (Bold, blue-underlined text is an addition; faded, red-underlined text is a ~~deletion~~.)
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A320255

a(n) = n! * [x^n] log(1 + exp(x)*(x + (n/2 - 1)*x^2)).
(history; published version)

#5 by Susanna Cuyler at Mon Oct 08 18:15:40 EDT 2018

STATUS

proposed

approved

#4 by Ilya Gutkovskiy at Mon Oct 08 13:13:23 EDT 2018

STATUS

editing

proposed

#3 by Ilya Gutkovskiy at Mon Oct 08 12:23:12 EDT 2018

CROSSREFS

Cf. A033464, A009306, A033464, A300455, A318118, A318124, A320254.

#2 by Ilya Gutkovskiy at Mon Oct 08 12:21:35 EDT 2018

NAME

allocated for Ilya Gutkovskiy

a(n) = n! * [x^n] log(1 + exp(x)*(x + (n/2 - 1)*x^2)).

DATA

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.

LINKS

N. J. A. Sloane, <a href="/transforms.txt">Transforms</a>

<a href="/index/Pol#polygonal_numbers">Index to sequences related to polygonal numbers</a>

MATHEMATICA

Table[n! SeriesCoefficient[Log[1 + Exp[x] (x + (n/2 - 1) x^2)], {x, 0, n}], {n, 0, 20}]

CROSSREFS

Cf. A033464, A009306, A300455, A318118, A318124, A320254.

KEYWORD

allocated

sign

AUTHOR

Ilya Gutkovskiy, Oct 08 2018

STATUS

approved

editing

#1 by Ilya Gutkovskiy at Mon Oct 08 12:21:35 EDT 2018

NAME

allocated for Ilya Gutkovskiy

KEYWORD

allocated

STATUS

approved