A385206 G.f. A(x) satisfies A(x) = ( 1 + 49*x*A(x) )^(1/7).

1, 7, -98, 1715, -28812, 369754, 0, -234003861, 11187831655, -379208609780, 10505577339166, -237021026782414, 3747904201751920, 0, -3136632447485449416, 165539296779239527515, -6087083256734433868530, 180571542422445599417377, -4318405727843353425012650

Offset

0,2

Links

Table of n, a(n) for n=0..18.

Index entries for reversions of series

Formula

a(n) = 49^n * binomial(n/7+1/7,n)/(n+1).

G.f. A(x) satisfies A(x) = 1/A(-x/A(x)^5).

G.f.: (1/x) * Series_Reversion(x/(1+49*x)^(1/7)).

a(7*n+6) = 0 for n >= 0.

Prog

(PARI) a(n) = 49^n*binomial(n/7+1/7, n)/(n+1);
(PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x/(1+49*x)^(1/7))/x)

Crossrefs

Cf. A385207, A385208.

Cf. A182122.

Sequence in context: A219406 A267664 A237022 * A156266 A234873 A051188

Adjacent sequences: A385203 A385204 A385205 * A385207 A385208 A385209

Keyword

sign

Author

Seiichi Manyama, Jun 21 2025

Status

approved