OFFSET
1,2
COMMENTS
It appears that a(n) = A153234(3*n-1). - Bruno Berselli, May 03 2011
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..200
Index entries for linear recurrences with constant coefficients, signature (8, 1, -8).
FORMULA
G.f.: x^2*(3 + 4*x)/((1 - x)*(1 + x)*(1 - 8*x)). - Adapted to the offset by Bruno Berselli, May 03 2011
a(2*k) = 8*a(2*k-1) + 3 and a(2*k+1) = 8*a(2*k) + 4 for k>0, a(1)=0. - Yosu Yurramendi, Dec 30 2016
MAPLE
MATHEMATICA
LinearRecurrence[{8, 1, -8}, {0, 3, 28}, 30] (* Harvey P. Dale, Oct 29 2023 *)
PROG
(PARI) a(n)=(8^n-(-1)^n-9)/18
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ralf Stephan, Nov 20 2010
STATUS
approved