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.

1, 2, 20, 684, 84864, 40783952, 78562790592, 613738473236928, 19459342629747109248, 2496653806284295319455488, 1291725241770954532057108070400, 2687434858858114549619735481969223680

Offset

1,2

Links

Table of n, a(n) for n=1..12.

Prog

(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)}

Crossrefs

Cf. A158269, A000108, A158825.

Sequence in context: A198761 A171799 A251183 * A168407 A333464 A356691

Adjacent sequences: A158265 A158266 A158267 * A158269 A158270 A158271

Keyword

nonn

Author

Paul D. Hanna, Mar 28 2009

Status

approved