

A274139


a(n) = 2^A000265(n) = 2^numerator(n/2^n), a sequence related to Oresme numbers.


0



2, 2, 8, 2, 32, 8, 128, 2, 512, 32, 2048, 8, 8192, 128, 32768, 2, 131072, 512, 524288, 32, 2097152, 2048, 8388608, 8, 33554432, 8192, 134217728, 128, 536870912, 32768, 2147483648, 2, 8589934592, 131072, 34359738368, 512, 137438953472, 524288, 549755813888, 32
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OFFSET

1,1


COMMENTS

Differences: 0, 6, 6, 30, 24, 120, 126, 510, 480, 2016, 2040, 8184, 8064, 32640, 32766, 131070, 130560, ...
GCD of differences is 6.


LINKS

Table of n, a(n) for n=1..40.
A. F. Horadam, Oresme numbers, Fib. Quart., 12 (1974), 267271.


FORMULA

a(n) = 2^denominator(2^n/n).
a(n) = 2^(n/2^valuation(n,2)) = 2^A007814(n).
a(n) = 2*A082392(n)^2 (conjecture).


MATHEMATICA

a[n_] := 2^(n/2^IntegerExponent[n, 2]);
Array[a, 40]


PROG

(PARI) a(n) = 2^(n/2^valuation(n, 2)); \\ Michel Marcus, Jun 12 2016


CROSSREFS

Cf. A000265, A006519, A007814, A082392.
Sequence in context: A245497 A086328 A095997 * A283995 A056189 A121860
Adjacent sequences: A274136 A274137 A274138 * A274140 A274141 A274142


KEYWORD

nonn


AUTHOR

JeanFrançois Alcover and Paul Curtz, Jun 11 2016


STATUS

approved



