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Search: id:A153854
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| A153854 |
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Nonzero coefficients of g.f.: A(x) = G(G(G(G(x)))) where G(x) = x + G(G(x))^3 is the g.f. of A153851. |
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+0
5
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| 1, 4, 42, 594, 9827, 179928, 3545637, 73988631, 1618178067, 36832568283, 868184365137, 21113629246953, 528282055072773, 13569770211307323, 357215846155083585, 9623529095387448543, 265025641890780905892
(list; graph; listen)
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OFFSET
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1,2
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FORMULA
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G.f.: A(x) = Sum_{n>=0} a(2n+1)*x^(2n+1) = G(G(G(G(x)))) where G(x) is the g.f. of A153851.
G.f.: A(x) = F(F(x)) where F(x) is the g.f. of A153852.
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EXAMPLE
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G.f.: A(x) = x + 4*x^3 + 42*x^5 + 594*x^7 + 9827*x^9 +...
A(x)^3 = x^3 + 12*x^5 + 174*x^7 + 2854*x^9 + 51045*x^11 +...
A(x) = G(G(G(G(x)))) where
G(x) = x + x^3 + 6*x^5 + 57*x^7 + 683*x^9 + 9474*x^11 +...
A(x) = H(H(x))) where H(x) = G(G(x)):
H(x) = x + 2*x^3 + 15*x^5 + 165*x^7 + 2213*x^9 + 33693*x^11 +...
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PROGRAM
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(PARI) {a(n)=local(G=x+O(x^(2*n+1))); for(i=0, n, G=serreverse(x-G^3)); polcoeff(subst(subst(G, x, G), x, subst(G, x, G)), 2*n-1)}
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CROSSREFS
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Cf. A153851, A153852, A153853, A153850.
Sequence in context: A092800 A156440 A151453 this_sequence A137645 A136045 A156453
Adjacent sequences: A153851 A153852 A153853 this_sequence A153855 A153856 A153857
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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), Jan 21 2009
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