|
Search: id:A128329
|
|
| |
|
| 1, 1, 4, 30, 321, 4389, 72512, 1399755, 30865353, 764755508, 21024535960, 634924059276, 20890221475598, 743727414390456, 28484480606420928, 1167761832049224515, 51022550712426870397, 2366859765773183488674
(list; graph; listen)
|
|
|
OFFSET
|
0,3
|
|
|
FORMULA
|
a(n) = [x^n] {1 + H(x)}, where H(x) is the (n+2)-th self-composition of G(x), and G(x) = x + x*G(G(x)) is the g.f. of A030266.
|
|
PROGRAM
|
(PARI) {a(n)=local(A=1+x, B); for(i=0, n, A=1+x*A*subst(A, x, x*A+x*O(x^n))); B=A; for(i=1, n, B=subst(B, x, x*A+x*O(x^n))); polcoeff(B, n)}
|
|
CROSSREFS
|
Cf. A030266; A128325 (table), A128326 (row 1), A128327 (row 2), A128328 (row 3).
Adjacent sequences: A128326 A128327 A128328 this_sequence A128330 A128331 A128332
Sequence in context: A088794 A052574 A139086 this_sequence A006149 A121413 A001761
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Paul D. Hanna (pauldhanna(AT)juno.com), Mar 11 2007
|
|
|
Search completed in 0.002 seconds
|
