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A363507
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G.f. satisfies A(x) = exp( Sum_{k>=1} (3 + A(x^k)) * x^k/k ).
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5
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1, 4, 14, 50, 191, 763, 3180, 13640, 59937, 268304, 1219626, 5614038, 26117296, 122598622, 579977691, 2762264225, 13234003724, 63737225733, 308406648979, 1498558628584, 7309116199687, 35772044402485, 175621484712091, 864670723348447
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OFFSET
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0,2
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LINKS
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FORMULA
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A(x) = Sum_{k>=0} a(k) * x^k = 1/(1-x)^3 * 1/Product_{k>=0} (1-x^(k+1))^a(k).
a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} ( 3 + Sum_{d|k} d * a(d-1) ) * a(n-k).
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PROG
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(PARI) seq(n) = my(A=1); for(i=1, n, A=exp(sum(k=1, i, (3+subst(A, x, x^k))*x^k/k)+x*O(x^n))); Vec(A);
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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