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 A159592 G.f.: Sum_{n>=0} a(n)*x^n/2^(n(n-1)/2) = exp( Sum_{n>=1} A(x/2^n)^n*x^n/n ). 1
 1, 1, 3, 17, 177, 3491, 133261, 9917307, 1443008813, 411772442315, 231163433300285, 255964900099068155, 560177408302962464013, 2427068640913282843197355, 20848444510025384551575108829 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Table of n, a(n) for n=0..14. EXAMPLE G.f.: A(x) = 1 + x + 3*x^2/2 + 17*x^3/2^3 + 177*x^4/2^6 + 3491*x^5/2^10 +... log(A(x)) = A(x/2)*x + A(x/4)^2*x^2/2 + A(x/8)^3*x^3/3 + A(x/16)^4*x^4/4 +... PROG (PARI) {a(n)=local(A=1+x); for(n=2, n, A=exp(sum(k=1, n, subst(A, x, x/2^k+x*O(x^n))^k*x^k/k))); 2^(n*(n-1)/2)*polcoeff(A, n)} CROSSREFS Cf. A157675. Sequence in context: A015083 A263460 A053934 * A126443 A054976 A304863 Adjacent sequences: A159589 A159590 A159591 * A159593 A159594 A159595 KEYWORD nonn AUTHOR Paul D. Hanna, May 02 2009 STATUS approved

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Last modified July 23 06:59 EDT 2024. Contains 374544 sequences. (Running on oeis4.)