login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A165259
Sum of odd powers of 4 and 9 divided by 13.
2
1, 61, 4621, 369181, 29821741, 2414250301, 195533302861, 15837861987421, 1282861452271981, 103911691734684541, 8416845656119913101, 681764476155480405661, 55222922216750191970221
OFFSET
0,2
FORMULA
G.f.: (1-36*x)/((1-16*x)*(1-81*x))
a(n) = 97*a(n-1) - 1296*a(n-2). - Harvey P. Dale, Jun 23 2013
E.g.f.: (1/13)*(4*exp(16*x) + 9*exp(81*x)). - G. C. Greubel, Mar 11 2023
MATHEMATICA
Table[(4^n+9^n)/13, {n, 1, 31, 2}] (* or *) LinearRecurrence[{97, -1296}, {1, 61}, 20] (* Harvey P. Dale, Jun 23 2013 *)
PROG
(PARI) a(n)=(4^(2*n+1)+9^(2*n+1))/13
(Magma) [(4^(2*n+1)+9^(2*n+1))/13: n in [0..30]]; // G. C. Greubel, Mar 11 2023
(SageMath) [(4^(2*n+1)+9^(2*n+1))/13 for n in range(31)] # G. C. Greubel, Mar 11 2023
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaume Oliver Lafont, Sep 11 2009
STATUS
approved