OFFSET
0,2
COMMENTS
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (0,8).
FORMULA
a(n) = (2*sqrt(2))^n*(1/2 - sqrt(2)/4) + (-2*sqrt(2))^n*(1/2 + sqrt(2)/4).
a(n) = (-2)^n * A016116(n). - R. J. Mathar, Apr 28 2008
a(n+3) = a(n+2)*a(n+1)/a(n). - Reinhard Zumkeller, Mar 04 2011
a(n) = Sum_{k=0..n} A158020(n,k)*3^k. - Philippe Deléham, Dec 01 2011
E.g.f.: cosh(2*sqrt(2)*x) - (1/sqrt(2))*sinh(2*sqrt(2)*x). - G. C. Greubel, Dec 04 2021
MATHEMATICA
LinearRecurrence[{0, 8}, {1, -2}, 40] (* G. C. Greubel, Dec 04 2021 *)
PROG
(Magma) [n le 2 select (-2)^(n-1) else 8*Self(n-2): n in [1..41]]; // G. C. Greubel, Dec 04 2021
(Sage) [(-2)^n*2^(n//2) for n in (0..40)] # G. C. Greubel, Dec 04 2021
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Apr 21 2004
STATUS
approved