Original entry on oeis.org
1, 2, 11, 97, 1145, 16796, 293623, 5950792, 137075837, 3535416136, 100902444181, 3156570232069, 107392381479683, 3947409366073512, 155880018189733841, 6581149438442041483, 295807451972657856921, 14102499966460374953016
Offset: 0
-
{a(n)=local(F=x, G=serreverse(x-x^2+O(x^(n+3))), M, N, P, m=n); M=matrix(m+2, m+2, r, c, F=x;for(i=1, r+c-2, F=subst(F, x, G+x*O(x^(m+3)))); polcoeff(F, c)); N=matrix(m+1, m+1, r, c, F=x;for(i=1, r, F=subst(F, x, G+x*O(x^(m+3)))); polcoeff(F, c)); P=matrix(n+1, n+1, r, c, M[r+1, c]); M=(P~*N~^-1); sum(k=1,n+1,M[n+1,k])}
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.
Original entry on oeis.org
1, 2, 20, 684, 84864, 40783952, 78562790592, 613738473236928, 19459342629747109248, 2496653806284295319455488, 1291725241770954532057108070400, 2687434858858114549619735481969223680
Offset: 1
-
{a(n)=local(G=serreverse(x-x^2+O(x^(n+2))));for(i=2,n,G=subst(G,x,G));polcoeff(G,n)}
A158269
a(n) = coefficient of x^n in the (2^n)-th iteration of x*C(x) where C(x) is the Catalan function (A000108), for n>=1.
Original entry on oeis.org
1, 4, 72, 4760, 1196800, 1185344160, 4704904407424, 75251548566631296, 4850542035077717613312, 1257976093502471658023554560, 1310350352604009611135942297681920
Offset: 1
-
{a(n)=local(G=serreverse(x-x^2+O(x^(n+2))));for(i=2,n+1,G=subst(G,x,G));polcoeff(G,n)}
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