A158268 - cp's OEIS frontend

A158268 a(n) = coefficient of x^n in the (2^(n-1))-th iteration of x*C(x) where C(x) is the Catalan function (A000108), for n>=1.

%I A158268 #2 Mar 30 2012 18:37:16
%S A158268 1,2,20,684,84864,40783952,78562790592,613738473236928,
%T A158268 19459342629747109248,2496653806284295319455488,
%U A158268 1291725241770954532057108070400,2687434858858114549619735481969223680
%N A158268 a(n) = coefficient of x^n in the (2^(n-1))-th iteration of x*C(x) where C(x) is the Catalan function (A000108), for n>=1.
%o A158268 (PARI) {a(n)=local(G=serreverse(x-x^2+O(x^(n+2))));for(i=2,n,G=subst(G,x,G));polcoeff(G,n)}
%Y A158268 Cf. A158269, A000108, A158825.
%K A158268 nonn
%O A158268 1,2
%A A158268 _Paul D. Hanna_, Mar 28 2009

cp's OEIS Frontend

A158268 a(n) = coefficient of x^n in the (2^(n-1))-th iteration of x*C(x) where C(x) is the Catalan function (A000108), for n>=1.