A133666 a(n) = a(n-1) - 16*a(n-2), a(0)=1, a(1)=4.

1, 4, -12, -76, 116, 1332, -524, -21836, -13452, 335924, 551156, -4823628, -13642124, 63535924, 281809908, -734764876, -5243723404, 6512514612, 90412089076, -13788144716, -1460381569932, -1239771254476, 22126333864436, 41962673936052

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Index entries for linear recurrences with constant coefficients, signature (1, -16).

Formula

G.f.: (1+3*x) / (1-x+16*x^2).

a(n) = Sum_{k=0..n} A133607(n,k)*4^k. - Philippe Deléham, Dec 29 2007

Crossrefs

Sequence in context: A190340 A232325 A291487 * A318432 A078628 A358660

Adjacent sequences: A133663 A133664 A133665 * A133667 A133668 A133669

Keyword

easy,sign

Author

Philippe Deléham, Dec 28 2007, corrected Jan 04 2008

Extensions

a(19) corrected and more terms from Sean A. Irvine, May 19 2019

Status

approved