

A175767


List of pairs of "twin numbers": Omega(n) = Omega(n  2^Omega(n)), where Omega is A001222.


0



3, 5, 5, 7, 6, 10, 11, 13, 10, 14, 17, 19, 12, 20, 21, 25, 22, 26, 20, 28, 29, 31, 34, 38, 35, 39, 24, 40, 41, 43, 42, 50, 44, 52, 51, 55, 40, 56, 59, 61, 58, 62, 65, 69, 71, 73, 68, 76, 70, 78, 48, 80, 82, 86, 87, 91, 91, 95, 84, 100, 101, 103, 88, 104, 107, 109, 102, 110, 80, 112, 111
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OFFSET

1,1


COMMENTS

The kprimes = numbers that are divisible by exactly k primes (counted with multiplicity).


LINKS

Table of n, a(n) for n=1..71.


FORMULA

a(2n+1) = A175766(n) = a(2n) + 2^A001222(a(2n+1)).


EXAMPLE

"Twin numbers" are (3, 5), (5, 7), (6, 10), (11, 13), (10, 14), (17, 19), (12, 20), (21, 25), (22, 26), (20, 28), (29, 31), (34, 38), (35, 39), (24, 40), (41, 43), (42, 50), (44, 52), (51, 55), (40, 56), (59, 61), (58, 62), (65, 69), (71, 73), ...


CROSSREFS

Cf. A175766, A001222, A077800, A175612, A175765.
Sequence in context: A285204 A086269 A057952 * A111800 A190136 A126611
Adjacent sequences: A175764 A175765 A175766 * A175768 A175769 A175770


KEYWORD

nonn


AUTHOR

JuriStepan Gerasimov, Sep 01 2010


EXTENSIONS

Rewritten by Charles R Greathouse IV, Sep 03 2010


STATUS

approved



