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A009576
Expansion of e.g.f. sinh(log(1+x))/cos(x).
1
0, 1, -1, 6, -18, 115, -615, 4732, -36148, 337797, -3315645, 37027826, -440999526, 5768129783, -80507865347, 1210608394920, -19345811001000, 329208442723465, -5922785067664185, 112578608999452894, -2251115252850724090
OFFSET
0,4
LINKS
FORMULA
a(n) ~ n! * (-1)^(n+1) / (2*cos(1)). - Vaclav Kotesovec, Jan 23 2015
MATHEMATICA
CoefficientList[Series[(x*(2 + x)*Sec[x])/(2*(1 + x)), {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)
With[{nmax = 50}, CoefficientList[Series[Sinh[Log[1 + x]]/Cos[x], {x, 0, nmax}], x]*Range[0, nmax]!] (* G. C. Greubel, Jan 21 208 *)
PROG
(PARI) x='x+O('x^30); concat([0], Vec(serlaplace(sinh(log(1+x))/cos(x)))) \\ G. C. Greubel, Jan 21 2018
CROSSREFS
Sequence in context: A108735 A143556 A007126 * A009580 A125839 A117813
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved