OFFSET
0,1
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) = b(3*n) + b(3*n + 1) + b(3*n + 2), where b(n) = A135530(n) [previous name].
a(n) = 7 * abs(A094014(n)).
O.g.f.: 7*(1 + 2*x)/(1 - 8*x^2). - R. J. Mathar, Feb 23 2008
From G. C. Greubel, Oct 18 2016: (Start)
a(n) = (7/4)*( (2 + sqrt(2)) + (-1)^n*(2 - sqrt(2)) )*(sqrt(2))^(3*n).
a(n) = 8*a(n-2).
E.g.f.: (7/2)*( 2*cosh(2*sqrt(2)*x) + sqrt(2)*sinh(2*sqrt(2)*x) ). (End)
MATHEMATICA
Table[(7/4)*( (2 + Sqrt[2]) + (-1)^n*(2 - Sqrt[2]) )*(Sqrt[2])^(3*n), {n, 0, 25}] (* or *) LinearRecurrence[{0, 8}, {7, 14}, 25] (* G. C. Greubel, Oct 18 2016 *)
PROG
(PARI) a(n)=([0, 1; 8, 0]^n*[7; 14])[1, 1] \\ Charles R Greathouse IV, Oct 18 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Feb 22 2008
EXTENSIONS
More terms from R. J. Mathar, Feb 23 2008
New name from G. C. Greubel, Oct 18 2016
STATUS
approved