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 A003723 E.g.f. exp(tanh(x)). (Formerly M4327) 6
 1, 1, 1, -1, -7, -3, 97, 275, -2063, -15015, 53409, 968167, -752343, -77000363, -166831871, 7433044411, 43685848289, -843598411471, -9398558916159, 107426835190735, 2116926930779225, -14072980460605907 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,5 COMMENTS Row sums of triangle A111593. REFERENCES N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence). LINKS T. D. Noe, Table of n, a(n) for n = 0..100 FORMULA a(n) := sum(m=1..n, sum(k=m..n, binomial(k-1,m-1)*k!*(-1)^(m+k)*2^(n-k)*Stirling2(n,k))/m!), n>0, a(0)=1. - Vladimir Kruchinin, Jun 28 2011 MATHEMATICA With[{nn = 30}, CoefficientList[Series[Exp[Tanh[x]], {x, 0, nn}], x] Range[0, nn]!] (* Vincenzo Librandi, Apr 11 2014 *) PROG (Maxima) a(n):=if n=0 then 1 else sum(sum(binomial(k-1, m-1)*k!*(-1)^(m+k)*2^(n-k)*stirling2(n, k), k, m, n)/m!, m, 1, n); /* Vladimir Kruchinin, Jun 28 2011 */ CROSSREFS Cf. A003706, A003710. Sequence in context: A248279 A183421 A173443 * A241438 A054471 A086453 Adjacent sequences:  A003720 A003721 A003722 * A003724 A003725 A003726 KEYWORD sign AUTHOR STATUS approved

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Last modified May 20 01:04 EDT 2022. Contains 353847 sequences. (Running on oeis4.)