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 A249737 E.g.f.: Product_{k=1..n} cosh(k*x). 2
 1, 0, 5, 0, 1992, 0, 6167551, 0, 73432708224, 0, 2389444075877425, 0, 173496878823412858880, 0, 24573448663070711791073155, 0, 6168942712247503719875933929472, 0, 2554865971518520622455831203134760669, 0, 1650933998542152349112398040415912949710848, 0 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Vaclav Kotesovec, Table of n, a(n) for n = 0..235 FORMULA If n is even a(n) ~ c * d^n * n^(2*n) / (2^(2*n-2) * exp(2*n)), where d = 8.9061971328050809899679389417314..., c = 1.004120096780056350248342856... MATHEMATICA Table[n!*SeriesCoefficient[Product[Cosh[k*x], {k, 1, n}], {x, 0, n}], {n, 0, 20}] nn = 20; tab = ConstantArray[0, nn]; tab[[1]] = Series[Cosh[x], {x, 0, nn}]; Do[tab[[k]] = Series[tab[[k-1]]*Cosh[k*x], {x, 0, nn}], {k, 2, nn}]; Flatten[{1, Table[k!*Coefficient[tab[[k]], x^k], {k, 1, nn}]}] (* more efficient *) CROSSREFS Cf. A249698, A177385, A177387, A001044 (e.g.f.: product_{k=1..n} sinh(k*x)). Sequence in context: A176327 A226156 A215616 * A129205 A098173 A180977 Adjacent sequences:  A249734 A249735 A249736 * A249738 A249739 A249740 KEYWORD nonn AUTHOR Vaclav Kotesovec, Nov 04 2014 STATUS approved

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Last modified January 19 09:35 EST 2019. Contains 319306 sequences. (Running on oeis4.)