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A159592
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G.f.: Sum_{n>=0} a(n)*x^n/2^(n(n-1)/2) = exp( Sum_{n>=1} A(x/2^n)^n*x^n/n ).
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1
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1, 1, 3, 17, 177, 3491, 133261, 9917307, 1443008813, 411772442315, 231163433300285, 255964900099068155, 560177408302962464013, 2427068640913282843197355, 20848444510025384551575108829
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OFFSET
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0,3
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LINKS
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EXAMPLE
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G.f.: A(x) = 1 + x + 3*x^2/2 + 17*x^3/2^3 + 177*x^4/2^6 + 3491*x^5/2^10 +...
log(A(x)) = A(x/2)*x + A(x/4)^2*x^2/2 + A(x/8)^3*x^3/3 + A(x/16)^4*x^4/4 +...
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PROG
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(PARI) {a(n)=local(A=1+x); for(n=2, n, A=exp(sum(k=1, n, subst(A, x, x/2^k+x*O(x^n))^k*x^k/k))); 2^(n*(n-1)/2)*polcoeff(A, n)}
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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