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Search: id:A145072
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| A145072 |
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G.f. satisfies: A(x) = (1+y)*A(y^2) where y = x*A(x). |
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1
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| 1, 1, 2, 5, 15, 48, 163, 573, 2074, 7669, 28860, 110148, 425384, 1659185, 6526791, 25863949, 103151955, 413728474, 1667757766, 6753022725, 27454555171, 112024545382, 458616153319, 1883201461892, 7754348091640, 32010908796160
(list; graph; listen)
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OFFSET
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0,3
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FORMULA
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G.f. satisfies: A(x) = A( [z/(1+z)]/A(x) )/(1+z) where z = sqrt(x).
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EXAMPLE
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A(x) = 1 + x + 2*x^2 + 5*x^3 + 15*x^4 + 48*x^5 + 163*x^6 + 573*x^7 +...
A([x/(1+x)]/A(x^2))/(1+x) = 1 + x^2 + 2*x^4 + 5*x^6 + 15*x^8 + 48*x^10 +...
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PROGRAM
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(PARI) {a(n)=local(A=1+x); for(n=1, n, A=1/x*serreverse(x/((1+x)*subst(A, x, x^2+x*O(x^n))))); polcoeff(A, n)}
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CROSSREFS
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Sequence in context: A149925 A149926 A071739 this_sequence A149927 A035350 A006570
Adjacent sequences: A145069 A145070 A145071 this_sequence A145073 A145074 A145075
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KEYWORD
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nonn
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AUTHOR
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Paul D. Hanna (pauldhanna(AT)juno.com), Oct 21 2008
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