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 A158838 Column 2 of triangle A158835. 4

%I

%S 1,3,21,217,2904,47337,906557,19910808,492818850,13564326950,

%T 410807572044,13573135469214,485765085176420,18717987193565613,

%U 772565258231236269,34002334709760133807,1589555183231724515700

%N Column 2 of triangle A158835.

%C Triangle A158835 transforms diagonals in the array A158825 of coefficients of successive iterations of x*C(x) where C(x) is the Catalan function (A000108).

%o (PARI) {a(n)=local(F=x, CAT=serreverse(x-x^2+x*O(x^(n+4))),M,N,P);M=matrix(n+4, n+4, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, CAT)); polcoeff(F, c)); N=matrix(n+3, n+3, r, c, M[r, c]); P=matrix(n+3, n+3, r, c, M[r+1, c]); (P~*N~^-1)[n+3,3]}

%Y Cf. A158835, A158836, A158837, A158839, A158840.

%K nonn

%O 0,2

%A _Paul D. Hanna_, Mar 28 2009

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Last modified February 27 01:52 EST 2020. Contains 332299 sequences. (Running on oeis4.)