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 A280777 Denominators of coefficients in asymptotic expansion of C_n (number of connected chord diagrams, A000699). 6
 1, 2, 8, 16, 128, 1280, 3072, 215040, 3440640, 2293760, 137625600, 201850880, 72666316800, 1889324236800, 52901078630400, 176336928768000, 135426761293824, 191854578499584000, 1593868805996544000, 787371190162292736000, 31494847606491709440000, 29395191099392262144000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Gheorghe Coserea, Table of n, a(n) for n = 0..101 Michael Borinsky, Generating asymptotics for factorially divergent sequences, arXiv preprint arXiv:1603.01236 [math.CO], 2016. EXAMPLE Coefficients are 1, -5/2, -43/8, -579/16, -44477/128, -5326191/1280, -180306541/3072, ... PROG (PARI) A000699_seq(N) = {   my(a = vector(N)); a[1] = 1;   for (n=2, N, a[n] = sum(k=1, n-1, (2*k-1)*a[k]*a[n-k])); a; }; seq(N) = my(C = 'x*Ser(A000699_seq(N))); Vec(x*exp(1-(2*C+C^2)/(2*x))/C); apply(denominator, seq(22)) \\ Gheorghe Coserea, Jan 22 2017 CROSSREFS Cf. A000699, A280775, A111111, A280776, A280778, A280779, A280780, A280781. Sequence in context: A199043 A046161 A092978 * A013516 A259688 A101059 Adjacent sequences:  A280774 A280775 A280776 * A280778 A280779 A280780 KEYWORD nonn,frac AUTHOR N. J. A. Sloane, Jan 19 2017 EXTENSIONS More terms from Gheorghe Coserea, Jan 22 2017 STATUS approved

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Last modified October 23 06:29 EDT 2018. Contains 316520 sequences. (Running on oeis4.)