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A205772
G.f. satisfies: A(x) = 1/Product_{n>=1} (1 - 2*x^n*A(x^n)).
2
1, 2, 10, 50, 290, 1766, 11442, 76522, 526574, 3697722, 26403186, 191072922, 1398344838, 10330855286, 76945148882, 577135722754, 4355579825058, 33050011129198, 251996066644866, 1929712025078322, 14834772898730766, 114445491235869774
OFFSET
0,2
EXAMPLE
G.f.: A(x) = 1 + 2*x + 10*x^2 + 50*x^3 + 290*x^4 + 1766*x^5 +...,
where A(x) = 1/((1 - 2*x*A(x)) * (1 - 2*x^2*A(x^2)) * (1 - 2*x^3*A(x^3)) * ...).
PROG
(PARI) {a(n)=local(A=1+x); for(i=1, n, A=1/prod(k=1, n, (1-2*x^k*subst(A, x, x^k+x*O(x^n))))); polcoeff(A, n)}
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Jan 31 2012
STATUS
approved