A049147 Revert transform of (1 - x - 4x^2 + x^3)/(1 - 6x^2).

1, 1, 0, 0, 2, 2, 4, 27, 78, 222, 816, 2736, 8784, 29704, 100408, 334889, 1128036, 3819368, 12912484, 43771606, 148863396, 506943540, 1729339848, 5911769970, 20242876176, 69422168880, 238465602096, 820352668488, 2826032713656

Offset

1,5

Links

Table of n, a(n) for n=1..29.

Index entries for reversions of series

Formula

Recurrence: 321*(n-2)*(n-1)*n*(2516020*n^4 - 31491772*n^3 + 145480151*n^2 - 293162531*n + 216592068)*a(n) = 2*(n-2)*(n-1)*(2526084080*n^5 - 35406865208*n^4 + 192331223572*n^3 - 503123551024*n^2 + 629426089443*n - 298978255044)*a(n-1) - 4*(n-2)*(2425443280*n^6 - 40059841328*n^5 + 266246046192*n^4 - 906854261524*n^3 + 1658235723203*n^2 - 1527014192298*n + 542466060192)*a(n-2) + 16*(1202657560*n^7 - 24072998716*n^6 + 201898038166*n^5 - 918651777571*n^4 + 2446500580654*n^3 - 3809962287592*n^2 + 3210482881323*n - 1128729779352)*a(n-3) - 144*(n-4)*(402563200*n^6 - 7051499520*n^5 + 49625121772*n^4 - 179334004260*n^3 + 350519357389*n^2 - 350728662015*n + 139913523792)*a(n-4) + 10368*(n-5)*(n-4)*(2*n - 11)*(2516020*n^4 - 21427692*n^3 + 66100955*n^2 - 86613465*n + 39933936)*a(n-5). - Vaclav Kotesovec, Jan 02 2021

Mathematica

Rest[CoefficientList[InverseSeries[Series[x*(1 - x - 4x^2 + x^3)/(1 - 6x^2), {x, 0, 40}], x], x]] (* Vaclav Kotesovec, Jan 02 2021 *)

Crossrefs

Sequence in context: A154594 A098335 A346714 * A189879 A189870 A257614

Adjacent sequences: A049144 A049145 A049146 * A049148 A049149 A049150

Keyword

nonn

Author

Olivier Gérard

Status

approved