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A336898
a(n) = numerator(n / (4^n - 2^n)) for n > 0 and a(0) = 1.
1
1, 1, 1, 3, 1, 5, 1, 7, 1, 9, 5, 11, 1, 13, 7, 15, 1, 17, 1, 19, 1, 3, 11, 23, 1, 25, 13, 27, 7, 29, 5, 31, 1, 33, 17, 35, 1, 37, 19, 39, 1, 41, 1, 43, 11, 45, 23, 47, 1, 49, 25, 51, 13, 53, 1, 55, 7, 57, 29, 59, 1, 61, 31, 9, 1, 65, 11, 67, 17, 69, 35, 71, 1, 73
OFFSET
0,4
EXAMPLE
r(n) = 1, 1/2, 1/6, 3/56, 1/60, 5/992, 1/672, 7/16256, 1/8160, 9/261632, ...
MAPLE
r := n -> `if`(n=0, 1, n/(4^n - 2^n)): seq(numer(r(n)), n=0..72);
PROG
(PARI) a(n) = if (n==0, 1, numerator(n / (4^n - 2^n))); \\ Michel Marcus, Aug 28 2020
CROSSREFS
Cf. A336899 (denominator).
Sequence in context: A340086 A307153 A339421 * A300330 A328478 A093411
KEYWORD
nonn,frac
AUTHOR
Peter Luschny, Aug 28 2020
STATUS
approved