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 A120783 Denominators of partial sums of Catalan numbers scaled by powers of 1/12. 5
 1, 12, 72, 1728, 10368, 41472, 248832, 11943936, 214990848, 2579890176, 15479341056, 371504185344, 2229025112064, 26748301344768, 53496602689536, 1711891286065152, 10271347716390912, 369768517790072832 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Numerators are given under A120782. It appears that the terms of this sequence are denominators of the power series expansion of 1+sqrt(x) at x=3, scaled by 1/(2*sqrt(3)). - Alexander R. Povolotsky, Mar 01 2016 LINKS G. C. Greubel, Table of n, a(n) for n = 0..925 FORMULA a(n) = denominator(r(n)), with the rationals r(n) = Sum_{k=0..n} C(k)/12^k with C(k) = A000108(k) (Catalan numbers). MATHEMATICA Denominator@ Table[Sum[CatalanNumber@ k/12^k, {k, 0, n}], {n, 0, 17}] (* Michael De Vlieger, Mar 03 2016 *) PROG (PARI) C(n) = binomial(2*n, n)/(n+1); \\ A000108 a(n) = denominator(sum(k=0, n, C(k)/12^k)); \\ Michel Marcus, Mar 02 2016 CROSSREFS Cf. A000108, A120782. Sequence in context: A143559 A341542 A120793 * A103475 A024014 A069039 Adjacent sequences: A120780 A120781 A120782 * A120784 A120785 A120786 KEYWORD nonn,frac,easy AUTHOR Wolfdieter Lang, Jul 20 2006 STATUS approved

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Last modified October 1 16:03 EDT 2023. Contains 365826 sequences. (Running on oeis4.)