

A141286


a(n) = the smallest positive multiple of n such that a(n) is divisible by A001222(a(n)), where A001222(m) is the sum of the exponents in the prime factorization of m.


1



2, 2, 3, 4, 5, 6, 7, 16, 18, 10, 11, 12, 13, 14, 30, 16, 17, 18, 19, 40, 42, 22, 23, 24, 75, 26, 27, 56, 29, 30, 31, 96, 66, 34, 105, 36, 37, 38, 78, 40, 41, 42, 43, 88, 45, 46, 47, 96, 147, 100, 102, 104, 53, 216, 165, 56, 114, 58, 59, 60, 61, 62, 63, 256, 195, 66, 67, 136, 138
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OFFSET

1,1


LINKS



EXAMPLE

For n = 25, checking: 1*25 = 25 = 5^2. The sum of the exponents in the primefactorization of 5^2 is 2. 2 does not divide 25. 2*25 = 50 = 2^1 *5^2. The sum of the exponents is 1+2=3. 3 does not divide 50. 3*25 = 75 = 3^1 *5^2. The sum of the exponents is 3. Now, 3 does divide 75. So a(25) = 75.


MAPLE

A001222 := proc(n) numtheory[bigomega](n) ; end: A141286 := proc(n) local k ; for k from 1 do if k*n > 1 then if (k*n) mod A001222(k*n) = 0 then RETURN( k*n ) ; fi; fi; od: end: seq(A141286(n), n=1..80) ; # R. J. Mathar, Feb 19 2009


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



