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%I #6 Mar 30 2012 18:55:30
%S 1,2,18,325,9050,342004,16332659,942562092,63762184160,4945947976997,
%T 432648272729266,42126940392610000,4518312124929961241,
%U 529235540464230162094,67213443963719684144890,9199173104526838608066833
%N Central coefficients of triangle A191490.
%H Vincenzo Librandi, <a href="/A191492/b191492.txt">Table of n, a(n) for n = 0..45</a>
%F a(n) = A191490(2*n,n).
%t f[n_, k_] := f[n, k] = f[n - 1, k] + (n - 1)f[n - 1, k - 1] + If[n == k, 1, 0]
%t f[_, 0] = 1;
%t f[0, _] = 0;
%t Table[f[2n, n], {n, 0, 100}]
%o (Maxima) P[0]:1$
%o P[n]:=(1+(n-1)*q)*P[n-1]+q^n$
%o makelist(coeff(expand(P[2*n]),q^n),n,0,12);
%Y Cf. A191490.
%K nonn
%O 0,2
%A _Emanuele Munarini_, Jun 03 2011
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