OFFSET
2,3
LINKS
J. Lansing, Largest Values for the Stern Sequence, J. Integer Seqs., 17 (2014), #14.7.5.
Index entries for linear recurrences with constant coefficients, signature (0,0,4,0,0,1).
FORMULA
G.f.: (x^2+x^3+2*x^4+2*x^6+x^7+2*x^10)/(1-4*x^3-x^6).
a(n) = 4*a(n-3) + a(n-6). - Harvey P. Dale, Apr 08 2015
a(3*n+1) = 2*Lucas(3*n-3) + Fibonacci(3*n-3)/2 for n>1. - Greg Dresden, Oct 17 2021
MAPLE
A244470 := proc(n)
coeftayl( (x^2+x^3+2*x^4+2*x^6+x^7+2*x^10)/(1-4*x^3-x^6), x=0, n) ;
end proc:
seq(A244470(n), n=1..50) ; # R. J. Mathar, Jul 05 2014
MATHEMATICA
CoefficientList[Series[(1 + x + 2*x^2 + 2*x^4 + x^5 + 2*x^8)/(1 - 4*x^3 - x^6), {x, 0, 30}], x] (* Wesley Ivan Hurt, Jul 05 2014 *)
LinearRecurrence[{0, 0, 4, 0, 0, 1}, {1, 1, 2, 4, 6, 9, 17, 25, 40}, 40] (* Harvey P. Dale, Apr 08 2015 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jul 01 2014
STATUS
approved