A126340 Largest coefficient of q in { [x^n] W(x,q) } where W(x,q) = exp( q*x*W(q*x,q) ); largest term in rows of triangle A126265.

1, 1, 2, 6, 28, 245, 2100, 26502, 371616, 6565104, 125017200, 2888063640, 71356079520, 2012272702440, 60689867021784, 2032123676705850, 72464991800160960, 2806386304260520800, 115406148262413677760

Offset

0,3

Links

Table of n, a(n) for n=0..18.

Example

a(n) appears to be divisible by n for n>0:
a(n)/n = [1,1,2,7,49,350,3786,46452,729456,12501720,262551240,...].

Prog

(PARI) {a(n)=local(W=1+x, V, H); for(i=0, n, W=exp(subst(x*W, x, q*x+x*O(x^n)))); V=Vec(Vec(W)[n+1]*n!+O(q^(n*(n+1)/2+1))); H=0; for(k=1, #V, if(V[k]>H, H=V[k])); H}

Crossrefs

Cf. A126265.

Sequence in context: A256599 A355208 A002047 * A370423 A355768 A277480

Adjacent sequences: A126337 A126338 A126339 * A126341 A126342 A126343

Keyword

nonn

Author

Paul D. Hanna, Dec 25 2006

Status

approved