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 A188489 Exponential transform of (A000275 number of pairs of permutations with rise/rise forbidden). 3
 1, 1, 2, 8, 61, 797, 16021, 457285, 17529203, 867230231, 53745914922, 4076301322848, 371301496685164, 39992538951200636, 5027440719872343598, 729432303460596468394, 120977789712983152108734, 22743262423568258626295550 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,3 LINKS Vaclav Kotesovec, Table of n, a(n) for n = 0..250 FORMULA G.f.: A(x) = exp( Sum_{n>=1} A000275(n)*x^n/n ) where A000275 is the number of pairs of permutations with rise/rise forbidden. a(n) ~ c * n! * (n-1)! / r^n, where r = 1/4*BesselJZero[0,1]^2 = 1.44579649073669613 and c = 1/(sqrt(r) * BesselJ(1, 2*sqrt(r))) = 1.6019746969280466266484... - Vaclav Kotesovec, Mar 02 2014, updated Apr 01 2018 EXAMPLE G.f.: A(x) = 1 + x + 2*x^2 + 8*x^3 + 61*x^4 + 797*x^5 + 16021*x^6 +... log(A(x)) = x + 3*x^2/2 + 19*x^3/3 + 211*x^4/4 + 3651*x^5/5 + 90921*x^6/6 +...+ A000275(n)*x^n/n +... PROG (PARI) {A000275(n)=n!^2*4^n*polcoeff(1/besselj(0, x+x*O(x^(2*n))), 2*n)} {a(n)=polcoeff(exp(sum(m=1, n, A000275(m)*x^m/m)+x*O(x^n)), n)} CROSSREFS Cf. A000275 (log), A115368. Sequence in context: A322012 A188324 A208356 * A085657 A005215 A058862 Adjacent sequences:  A188486 A188487 A188488 * A188490 A188491 A188492 KEYWORD nonn AUTHOR Paul D. Hanna, Apr 01 2011 STATUS approved

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Last modified September 16 18:26 EDT 2021. Contains 347473 sequences. (Running on oeis4.)