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