A152554 - OEIS

%I #4 Jul 11 2015 16:20:43

%S 1,1,3,16,180,2640,52934,1307556,39067428,1369499060,54995284784,

%T 2507211396061,127388480252917,7144814127814222,439553511977812220,

%U 29347225935730588372,2116793087420823777580,164035715631344596393196

%N Largest term in row n of triangle A152550.

%C Compare to row sums of triangle A152550: (2n+1)^(n-1).

%C Triangle A152550 lists coefficients in a q-analog of the function [LambertW(-2x)/(-2x)]^(1/2).

%o (PARI) {a(n)=local(e_q=1+sum(j=1,n,x^j/prod(i=1,j,(q^i-1)/(q-1))), LW2_q=sqrt(serreverse(x/(e_q+x*O(x^n))^2)/x)); vecsort(Vec(polcoeff(LW2_q+x*O(x^n),n,x)*prod(i=1,n,(q^i-1)/(q-1))))[n*(n-1)/2+1]}

%Y Cf. A152550, A152551 (q=-1), A152552 (q=2), A152553 (q=3).

%K nonn

%O 0,3

%A _Paul D. Hanna_, Dec 07 2008