A277299 - OEIS

A277299

Central terms of triangle A277295 in even-indexed rows; a(n) = A277295(2*n,n-1).

1, 14, 698, 56410, 6036632, 784844330, 118467338692, 20204403241014, 3825143045741850, 794096638401382028, 179152196191253429864, 43621984527307144281094, 11400895235718650585287660, 3183846191638117842792003252, 946381984098376099573619213864, 298412976572690317096982653746772

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OFFSET

1,2

COMMENTS

G.f. G(x,y) of triangle A277295 satisfies:

(1) G(x,y) = x + G( y*G(x,y) + (1-y)*x, y)^2.

(2) G( x - y*G(x,y)^2, y) = x + (1-y)*G(x,y)^2.

LINKS

Table of n, a(n) for n=1..16.

PROG

(PARI) {A277295(n, k) = my(A=x); for(i=1, n, A = x + subst(A^2, x, y*A + (1-y)*x +x*O(x^n)) ); polcoeff(polcoeff(A, n, x), k, y)}

for(n=1, 20, print1(A277295(2*n, n-1), ", "))