A124023 G.f.: 1/(1-2*x-6*x^2+4*x^3).

1, 2, 10, 28, 108, 344, 1224, 4080, 14128, 47840, 164128, 558784, 1910976, 6518144, 22267008, 75998976, 259527424, 885980672, 3025129984, 10328034304, 35262925824, 120393537536, 411052492800, 1403414507520, 4791569821696, 16359416717312, 55854594334720

Offset

0,2

Links

Table of n, a(n) for n=0..26.

Index entries for linear recurrences with constant coefficients, signature (2,6,-4).

Mathematica

f[x_] = -4 + 6 x + 2 x^2 - x^3; g[x_] = ExpandAll[x^3*f[1/x]]; Table[ SeriesCoefficient[Series[x/(g[x]), {x, 0, 30}], n], {n, 0, 30}]

Crossrefs

Sequence in context: A291053 A104657 A000900 * A127921 A371943 A106184

Adjacent sequences: A124020 A124021 A124022 * A124024 A124025 A124026

Keyword

nonn,easy

Author

Roger L. Bagula and Gary W. Adamson, Oct 31 2006

Extensions

Edited by N. J. A. Sloane, Nov 04 2006

Status

approved