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A191492
Central coefficients of triangle A191490.
2
1, 2, 18, 325, 9050, 342004, 16332659, 942562092, 63762184160, 4945947976997, 432648272729266, 42126940392610000, 4518312124929961241, 529235540464230162094, 67213443963719684144890, 9199173104526838608066833
OFFSET
0,2
LINKS
FORMULA
a(n) = A191490(2*n,n).
MATHEMATICA
f[n_, k_] := f[n, k] = f[n - 1, k] + (n - 1)f[n - 1, k - 1] + If[n == k, 1, 0]
f[_, 0] = 1;
f[0, _] = 0;
Table[f[2n, n], {n, 0, 100}]
PROG
(Maxima) P[0]:1$
P[n]:=(1+(n-1)*q)*P[n-1]+q^n$
makelist(coeff(expand(P[2*n]), q^n), n, 0, 12);
CROSSREFS
Cf. A191490.
Sequence in context: A229490 A192985 A193264 * A090307 A123311 A349881
KEYWORD
nonn
AUTHOR
Emanuele Munarini, Jun 03 2011
STATUS
approved