A107385 a(n) = a(n-1)+4*a(n-2)-4*a(n-4).

0, 1, 1, 2, 6, 10, 30, 62, 158, 366, 878, 2094, 4974, 11886, 28270, 67438, 160622, 382830, 912238, 2173806, 5180270, 12344174, 29416302, 70097774, 167041902, 398056302, 948558702, 2260392814, 5386460014, 12835806062, 30587411310

Offset

0,4

Links

Table of n, a(n) for n=0..30.

Index entries for linear recurrences with constant coefficients, signature (1,4,0,-4).

Formula

Limit a(n)/a(n-1) = 2.3829757679...

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

Mathematica

m = 4 a[0] = 0; a[1] = 1; a[2] = 1; a[3] = 2; a[n_] := a[n] = a[n - 1] + m*a[n - 2] - m*a[n - 4] digits = 50 aa = Table[a[n], {n, 0, digits}]
LinearRecurrence[{1, 4, 0, -4}, {0, 1, 1, 2}, 40] (* Harvey P. Dale, Oct 29 2018 *)

Crossrefs

Sequence in context: A246349 A026117 A283909 * A342125 A332321 A283846

Adjacent sequences: A107382 A107383 A107384 * A107386 A107387 A107388

Keyword

nonn,easy

Author

Roger L. Bagula, May 24 2005

Extensions

Definition replaced by recurrence by the Associate Editors of the OEIS, Sep 28 2009

Status

approved