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A158837
Column 1 of triangle A158835.
5
1, 2, 11, 94, 1072, 15212, 257777, 5074738, 113775490, 2861365660, 79763482974, 2440866020252, 81343355108428, 2932370770780016, 113695507437209845, 4717853729131352186, 208615291319607614600, 9792578421235713418464
OFFSET
0,2
COMMENTS
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).
PROG
(PARI) {a(n)=local(F=x, CAT=serreverse(x-x^2+x*O(x^(n+3))), M, N, P); M=matrix(n+3, n+3, r, c, F=x; for(i=1, r+c-2, F=subst(F, x, CAT)); polcoeff(F, c)); N=matrix(n+2, n+2, r, c, M[r, c]); P=matrix(n+2, n+2, r, c, M[r+1, c]); (P~*N~^-1)[n+2, 2]}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Mar 28 2009
STATUS
approved