A049144 Revert transform of (1 + x - 2x^2 + x^3)/(1 + 2x).

1, 1, 2, 4, 10, 24, 64, 167, 460, 1256, 3532, 9910, 28280, 80756, 232984, 673371, 1958982, 5710900, 16722156, 49061276, 144387320, 425674212, 1257774336, 3721938064, 11032243612, 32740524236, 97287632048, 289369653892

Offset

1,3

Links

Table of n, a(n) for n=1..28.

Index entries for reversions of series

Formula

Recurrence: 31*(n-2)*(n-1)*n*(472*n^3 - 4608*n^2 + 14891*n - 15930)*a(n) = 4*(n-2)*(n-1)*(12272*n^4 - 138216*n^3 + 563902*n^2 - 975864*n + 591975)*a(n-1) + 72*(n-2)*(1416*n^5 - 19488*n^4 + 106149*n^3 - 285989*n^2 + 380822*n - 200250)*a(n-2) - 8*(35872*n^6 - 619248*n^5 + 4419892*n^4 - 16684488*n^3 + 35101288*n^2 - 38981571*n + 17829450)*a(n-3) - 48*(n-4)*(3*n - 13)*(3*n - 11)*(472*n^3 - 3192*n^2 + 7091*n - 5175)*a(n-4). - Vaclav Kotesovec, Jan 02 2021

Mathematica

Rest[CoefficientList[InverseSeries[Series[x*(1 + x - 2x^2 + x^3)/(1 + 2x), {x, 0, 40}], x], x]] (* Vaclav Kotesovec, Jan 02 2021 *)

Crossrefs

Sequence in context: A007874 A294410 A121704 * A354733 A336419 A049131

Adjacent sequences: A049141 A049142 A049143 * A049145 A049146 A049147

Keyword

nonn

Author

Olivier Gérard

Status

approved