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 A300589 a(n) = A300617(n) / (n*(n+1)/2) for n>=1. 2
 1, 1, 5, 55, 1025, 28638, 1117831, 58157100, 3895841625, 327054041995, 33660663702514, 4170641243258042, 612634528823952155, 105303950053511041900, 20943400410601239618360, 4772694556432364600596272, 1235587041134996933696367753, 360653856192923791041427500825, 117894515649092645422159124253775, 42901062533218086978322192560871705 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS It is conjectured that this sequence consists entirely of integers. O.g.f. G(x) of A300617 satisfies: [x^n] exp(n*G(x)) = n^2 * [x^(n-1)] exp(n*G(x)) for n>=1. LINKS Paul D. Hanna, Table of n, a(n) for n = 1..300 PROG (PARI) {a(n) = my(A=[1]); for(i=1, n+1, A=concat(A, 0); V=Vec(Ser(A)^(#A-1)); A[#A] = ((#A-1)^2*V[#A-1] - V[#A])/(#A-1) ); polcoeff( log(Ser(A)), n) / (n*(n+1)/2)} for(n=1, 20, print1(a(n), ", ")) CROSSREFS Cf. A300617, A300616. Sequence in context: A266481 A006150 A140049 * A130031 A336289 A119399 Adjacent sequences:  A300586 A300587 A300588 * A300590 A300591 A300592 KEYWORD nonn AUTHOR Paul D. Hanna, Mar 10 2018 STATUS approved

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Last modified September 16 07:19 EDT 2021. Contains 347469 sequences. (Running on oeis4.)