A049132 Revert transform of (-1 + 3x^2)/(-1 - x + 4x^2 + x^3).

1, 1, 0, 0, 2, 2, 3, 19, 42, 82, 280, 768, 1807, 5167, 14713, 38361, 105722, 299954, 821480, 2272736, 6422244, 17979356, 50311418, 142328594, 402652059, 1137986155, 3232284414, 9201271726, 26196062383, 74759129271, 213809119056

Offset

1,5

Links

Table of n, a(n) for n=1..31.

Index entries for reversions of series

Formula

Recurrence: 36*(n-1)*n*(164576*n^2 - 967941*n + 1382068)*a(n) = 12*(n-1)*(1810336*n^3 - 13115991*n^2 + 29562932*n - 20183280)*a(n-1) - (24850976*n^4 - 235688435*n^3 + 765601300*n^2 - 983615557*n + 386051316)*a(n-2) + (95947808*n^4 - 1082888579*n^3 + 4400606200*n^2 - 7566881293*n + 4579056084)*a(n-3) - (n-4)*(188439520*n^3 - 1628681757*n^2 + 4148407868*n - 3159561891)*a(n-4) + 321*(n-5)*(n-4)*(164576*n^2 - 638789*n + 578703)*a(n-5). - Vaclav Kotesovec, Jan 02 2021

Mathematica

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

Crossrefs

Sequence in context: A348667 A230504 A265806 * A184846 A323609 A087768

Adjacent sequences: A049129 A049130 A049131 * A049133 A049134 A049135

Keyword

nonn

Author

Olivier Gérard

Status

approved