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A037484
Base 7 digits are, in order, the first n terms of the periodic sequence with initial period 1,2.
0
1, 9, 64, 450, 3151, 22059, 154414, 1080900, 7566301, 52964109, 370748764, 2595241350, 18166689451, 127166826159, 890167783114, 6231174481800, 43618221372601, 305327549608209, 2137292847257464
OFFSET
1,2
FORMULA
a(n) = 7a(n-1) + a(n-2) - 7a(n-3).
a(n) = (-1)^n/16 -1/4 +3*7^n/16. G.f. x*(1+2*x) / ( (x-1)*(7*x-1)*(1+x) ). - R. J. Mathar, Nov 02 2011
CROSSREFS
Sequence in context: A231822 A049684 A037540 * A378566 A013566 A056769
KEYWORD
nonn,base,easy
STATUS
approved