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Search: id:A132330
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| A132330 |
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G.f.: A(x) = 1 + x*(A_2)^3; A_2 = 1 + x^2*(A_3)^3; A_3 = 1 + x^3*(A_4)^3; ... A_n = 1 + x^n*(A_{n+1})^3 for n>=1 with A_1 = A(x). |
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+0
2
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| 1, 1, 0, 3, 0, 3, 9, 1, 18, 9, 36, 45, 57, 90, 114, 351, 165, 558, 738, 1044, 1791, 1908, 3915, 4926, 8568, 8553, 17217, 26271, 30474, 50967, 68526, 113319, 144324, 219195, 299359, 473454, 665424, 860733, 1396350, 1895913, 2762550, 3790935, 5695974
(list; graph; listen)
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OFFSET
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0,4
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FORMULA
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G.f. A(x) = B(x,x), where B(w,x) satisfies the functional equation B(w,x) = 1 + x*B(w,wx)^3. B(w,x) is the g.f. for the number of ternary trees of given path length and number of nodes; B(1,x) is the g.f. for A001764.
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PROGRAM
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(PARI) {a(n)=local(A=1+x*O(x^n)); for(j=0, n-1, A=1+x^(n-j)*A^3); polcoeff(A, n)}
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CROSSREFS
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Cf. A132331 (cube); A001764; A108643 (variant).
Sequence in context: A117940 A099093 A137339 this_sequence A117078 A021333 A104141
Adjacent sequences: A132327 A132328 A132329 this_sequence A132331 A132332 A132333
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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), Aug 20 2007
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