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A275255 G.f.: A(x) = x*Product_{n>=1} (1+a(n)^2*x^n) = Sum_{n>=1} a(n)*x^n. 0

%I

%S 1,1,1,2,5,30,930,865833,749667649743,562001585071942995616767,

%T 315845781623376380137718569771289227717728016656

%N G.f.: A(x) = x*Product_{n>=1} (1+a(n)^2*x^n) = Sum_{n>=1} a(n)*x^n.

%F G.f.: A(x) = x*Product_{n>=1} (1+a(n)^2*x^n) = Sum_{n>=1} a(n)*x^n.

%e a(1)=a(2)=a(3)=1.

%e a(4)=a(1)^2*a(2)^2+a(3)^2=2.

%e a(5)=a(1)^2*a(3)^2+a(4)^2=5.

%t num = 10; g = Table[1, {n, 1, num}]; g[[1]] = Table[1, {n, 1, num}];

%t For[i = 2, i <= num, i++,g[[i]] = Table[CoefficientList[Series[Product[(1 + g[[i - 1]][[k]]^2 x^k), {k, 1, num}], {x, 0,num}], x][[n]], {n, 1, num}];]; g[[num]]

%Y Cf. A032305 for a similar g.f. property.

%K nonn

%O 1,4

%A _Benedict W. J. Irwin_, Jul 21 2016

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Last modified October 1 19:48 EDT 2022. Contains 357172 sequences. (Running on oeis4.)