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A009585
E.g.f. sinh(log(1+x)^2).
3
0, 0, 2, -6, 22, -100, 668, -6048, 64776, -763488, 9676152, -131167080, 1900043880, -29387788560, 484545133200, -8496674716320, 158018410132800, -3107703909004800, 64445168622156960, -1405303346393768160
OFFSET
0,3
LINKS
FORMULA
a(n) = Sum_{j=1..(n+1)/2} (4*j-2)!/(2*j-1)!*stirling1(n,4*j-2)), n>0, a(0) = 0. - Vladimir Kruchinin, Jun 08 2011
EXAMPLE
sinh(log(x+1)^2) = 2/2!*x^2-6/3!*x^3+22/4!*x^4-100/5!*x^5...
MATHEMATICA
With[{nmax = 50}, CoefficientList[Series[Sinh[Log[1 + x]^2], {x, 0, nmax}], x]*Range[0, nmax]!] (* G. C. Greubel, Jan 22 2018 *)
PROG
(Maxima) a(n):=sum((4*j-2)!/(2*j-1)!*stirling1(n, 4*j-2), j, 1, (n+1)/2); /* Vladimir Kruchinin, Jun 08 2011 */
(PARI) x='x+O('x^30); concat([0], Vec(serlaplace(sinh(log(1+x)^2)))) \\ G. C. Greubel, Jan 22 2018
CROSSREFS
Sequence in context: A052517 A245119 A012270 * A012267 A012268 A009655
KEYWORD
sign,easy
AUTHOR
EXTENSIONS
Extended with signs by Olivier Gérard, Mar 15 1997
STATUS
approved