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A053485
Denominators in expansion of exp(2x)/(1-x).
3
1, 1, 1, 3, 1, 15, 45, 21, 315, 2835, 4725, 22275, 93555, 2027025, 42567525, 638512875, 212837625, 2170943775, 13956067125, 618718975875, 9280784638125, 14992036723125, 7522320180375, 49308808782358125, 147926426347074375
OFFSET
0,4
LINKS
FORMULA
a(n) = denominator( Sum_{k=0..n} 2^k/k! ). - G. C. Greubel, Jan 18 2017
MATHEMATICA
Denominator[Table[Sum[2^k/k!, {k, 0, n}], {n, 0, 50}]] (* G. C. Greubel, Jan 18 2017 *)
PROG
(PARI) for(n=0, 25, print1(denominator(sum(k=0, n, 2^k/k!)), ", ")) \\ G. C. Greubel, Jan 18 2017
CROSSREFS
Sequence in context: A365338 A089278 A213245 * A160628 A160604 A160616
KEYWORD
nonn,frac
AUTHOR
N. J. A. Sloane, Jan 15 2000
STATUS
approved