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Search: id:A120574
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| A120574 |
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G.f. satisfies: A(x) = x + x*A(x) + x*A(A(x)). |
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+0
2
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| 1, 2, 6, 26, 146, 978, 7454, 62882, 576914, 5687506, 59732838, 664040698, 7775333858, 95517840738, 1227175022334, 16444901577858, 229338157229154, 3321917275376098, 49890293296044806, 775682898796646810
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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A(x) = x + 2*x^2 + 6*x^3 + 26*x^4 + 146*x^5 + 978*x^6 + 7454*x^7 +...
A(A(x)) = x + 4*x^2 + 20*x^3 + 120*x^4 + 832*x^5 + 6476*x^6 +...
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PROGRAM
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(PARI) {a(n)=local(F=x+x*O(x^n), G=F); for(i=1, n, F=x+x*F+x*subst(F, x, F)); polcoeff(F, n)}
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CROSSREFS
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Cf. A120575.
Sequence in context: A009575 A127116 A107404 this_sequence A002710 A132609 A125224
Adjacent sequences: A120571 A120572 A120573 this_sequence A120575 A120576 A120577
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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), Jun 15 2006
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