

A248592


Denominators of the (simplified) rational numbers n*2^(n  1)/(n  1)! .


4



1, 1, 1, 3, 3, 5, 45, 315, 35, 567, 14175, 51975, 467775, 868725, 2837835, 638512875, 638512875, 1206079875, 97692469875, 371231385525, 441942125625, 17717861581875, 2143861251406875, 16436269594119375, 5917057053882975, 284473896821296875, 1780595872696265625
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OFFSET

1,4


LINKS

Table of n, a(n) for n=1..27.
James Burling, Another Special Rational Sequence


FORMULA

a(n) = denom(n * 2^(n  1) / (n  1)!).
a(n) = denom(g(1, n)) where g(m, n) = m if m = n; 2g(m + 1, n)/m otherwise.


MAPLE

A248592 := proc(n)
n*2^(n1)/(n1)! ;
denom(%) ;
end proc:
seq(A248592(n), n=1..30) ; # R. J. Mathar, Oct 10 2014


PROG

(PARI) vector(40, n, denominator(n*2^(n  1)/(n  1)!)) \\ Michel Marcus, Oct 09 2014


CROSSREFS

Cf. A248591 (numerators).
Has same start as A241591 but is a different sequence.
Sequence in context: A170919 A280779 A241591 * A132809 A265960 A279062
Adjacent sequences: A248589 A248590 A248591 * A248593 A248594 A248595


KEYWORD

frac,nonn


AUTHOR

James Burling, Oct 09 2014


EXTENSIONS

More terms from Michel Marcus, Oct 09 2014


STATUS

approved



