A277296 - OEIS

A277296

Column 2 of triangle A277295; a(n) = A277295(n+2,2).

0, 5, 76, 698, 5088, 32461, 189940, 1046190, 5511440, 28061890, 139089880, 674600980, 3213923072, 15084364221, 69904629316, 320443984742, 1455102018480, 6553035703798, 29296998868904, 130133568013164, 574698326054848, 2524813186117010, 11040163152179976, 48069234287414668, 208481908639356448, 900995206054983396, 3881108155492099760

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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..27.

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, 30, print1(A277295(n+2, 2), ", "))