A120976 G.f. satisfies: A(x/A(x)^5) = 1 + x ; thus A(x) = 1 + series_reversion(x/A(x)^5).

1, 1, 5, 60, 1060, 23430, 602001, 17281760, 541258390, 18210836060, 651246905140, 24566101401035, 971933892729980, 40156993344526860, 1726753293393763625, 77065076699967844390, 3561820706538663354320, 170162336673835615653925

Offset

0,3

Links

Table of n, a(n) for n=0..17.

Formula

G.f. satisfies: A(x) = 1 + x*B(x)^5 = 1 + (1 + x*C(x)^5 )^5 where B(x) and C(x) satisfy: C(x) = B(x)*B(A(x)-1), B(x) = A(A(x)-1), B(A(x)-1) = A(B(x)-1), B(x/A(x)^5) = A(x), B(x) = A(x*B(x)^5) and B(x) is g.f. of A120977.

Prog

(PARI) {a(n)=local(A=[1, 1]); for(i=2, n, A=concat(A, 0); A[ #A]=-Vec(subst(Ser(A), x, x/Ser(A)^5))[ #A]); A[n+1]}

Crossrefs

Cf. A120977; variants: A120970, A120972, A120974, A030266, A067145, A107096.

Sequence in context: A156125 A260776 A128574 * A062980 A365557 A113665

Adjacent sequences: A120973 A120974 A120975 * A120977 A120978 A120979

Keyword

nonn

Author

Paul D. Hanna, Jul 20 2006

Status

approved