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A275752
Self-convolution square root of the odd bisection of A274965.
3
1, 2, 8, 36, 166, 770, 3574, 16560, 76516, 352498, 1619014, 7414134, 33855996, 154181234, 700333366, 3173299648, 14345094004, 64704125888, 291235313046, 1308229210186, 5865335253474, 26248821086374, 117265700856282, 523010482541564, 2328947839518852, 10354971182171076, 45973304229373220, 203824525466826232, 902455230607927616, 3990584636812405052, 17624255201680536016
OFFSET
0,2
COMMENTS
The g.f. of A274965 equals G(x,1), where G(x,y) = x*y + G(x,x*y)^2 is the g.f. of A275670.
LINKS
EXAMPLE
G.f.: A(x) = 1 + 2*x + 8*x^2 + 36*x^3 + 166*x^4 + 770*x^5 + 3574*x^6 + 16560*x^7 + 76516*x^8 + 352498*x^9 + 1619014*x^10 + 7414134*x^11 + 33855996*x^12 +...
where
A(x)^2 = 1 + 4*x + 20*x^2 + 104*x^3 + 540*x^4 + 2780*x^5 + 14180*x^6 + 71688*x^7 + 359452*x^8 + 1788988*x^9 + 8844064*x^10 +...+ A274965(2*n+1)*x^n +...
PROG
(PARI) {a(n) = my(A, B=1); for(k=0, 2*n, B = B^2 + x^(2*n+1-k) +O(x^(2*n+2))); A = sqrt( (B - subst(B, x, -x))/(2*x) ); polcoeff(A, 2*n)}
for(n=0, 30, print1(a(n), ", "))
CROSSREFS
Sequence in context: A147722 A089387 A206902 * A084868 A350645 A330793
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Aug 14 2016
STATUS
approved