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A270568
Expansion of (1+4*x)/(1-8*x).
2
1, 12, 96, 768, 6144, 49152, 393216, 3145728, 25165824, 201326592, 1610612736, 12884901888, 103079215104, 824633720832, 6597069766656, 52776558133248, 422212465065984, 3377699720527872, 27021597764222976, 216172782113783808, 1729382256910270464
OFFSET
0,2
COMMENTS
Partial sums are 1, 13, 109, 877, 7021, 56173, ...
FORMULA
G.f.: (1+4*x) / (1-8*x).
a(n) = 8*a(n-1) for n>1.
a(n) = 12*8^(n-1) for n>0.
a(n) = A094085(n), n>1. - R. J. Mathar, Mar 21 2016
MATHEMATICA
CoefficientList[Series[(1 + 4 x)/(1 - 8 x), {x, 0, 20}], x] (* Michael De Vlieger, Mar 19 2016 *)
Join[{1}, NestList[8#&, 12, 30]] (* Harvey P. Dale, Oct 05 2022 *)
PROG
(PARI) Vec((1+4*x)/(1-8*x) + O(x^30))
CROSSREFS
Cf. A001018 (powers of 8), A204623.
Sequence in context: A073392 A038845 A204623 * A223151 A155620 A219438
KEYWORD
nonn,easy
AUTHOR
Colin Barker, Mar 19 2016
STATUS
approved