A309564 Shifts left by 3 places under series reversion.

1, 1, 1, 1, -1, 1, -1, 3, -15, 59, -189, 567, -1863, 7141, -29817, 125919, -528329, 2238303, -9769917, 44312225, -208177669, 1005840685, -4972561375, 25105651267, -129470605611, 682486916465, -3678964401327, 20276967904907, -114199064797229, 656666370592173

Offset: 1

Author

Vladimir Reshetnikov, Aug 08 2019

Keywords

• sign

Comments

Series reversion of the g.f. gives the same sequence with three initial terms (1, 1, 1) dropped.

Crossrefs

Cf. A067145, A309254.

Programs

Mathematica

Nest[InverseSeries[#] x^3 + x^3 + x^2 + x &, x + O[x]^2, 10][[3]]

Formula

G.f. satisfies A((A(x) - x - x^2 - x^3)/x^3) = x.