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A069120
Integers of the form k!*sum(i=1..k, 1/(i*2^i) ).
2
4, 3489, 906408439650, 17919252390718041882750, 5699637429226533498825333877162500, 179263970680739996376691111034230475370480684738369155859375
OFFSET
1,1
LINKS
EXAMPLE
4 is in the sequence because for k = 3, 3!*(1/1/2^1 + 1/2/2^2 + 1/3/2^3) = 4 is an integer. - Robert Israel, May 18 2014
MAPLE
select(type, [seq](k!*add(1/i/2^i, i=1..k), k=1..100), integer); # Robert Israel, May 18 2014
CROSSREFS
Cf. A069119.
Sequence in context: A247154 A134908 A114498 * A221191 A110104 A024061
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Apr 07 2002
STATUS
approved