

A116991


a(1)=1. a(n) = number of this sequence's terms a(m), 1<= m <= n1, each with b(a(m),p) not equal to each b(n,p) for every prime p dividing n, where p^b(k,p) is the highest power of the prime p to divide k.


1



1, 1, 2, 3, 4, 3, 6, 7, 8, 7, 10, 7, 12, 7, 9, 15, 16, 13, 18, 15, 10, 16, 22, 16, 24, 18, 26, 21, 28, 14, 30, 31, 22, 22, 22, 29, 36, 24, 26, 31, 40, 14, 42, 35, 33, 29, 46, 32, 48, 32, 37, 44, 52, 36, 41, 41, 43, 38, 58, 36, 60, 40, 46, 63, 51, 32, 66, 57, 49, 35, 70, 59, 72
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OFFSET

1,3


LINKS

Owen Whitby, Table of n, a(n) for n = 1..500


EXAMPLE

Among the sequence's first 11 terms there are 7 terms that share no common primepower in their primefactorization with the primepowers in the primefactorization of 12. 12 = 2^2 *3^1. The 7 terms sharing no primepower with 12 are 1, 1, 2, 7, 8, 7 and 10. The other 4 terms (3, 4, 3 and 6) each share at least one primepower with 12 in the integers' primefactorizations.


MATHEMATICA

alist={1}; flist={{{1, 1}}}; Do[a=Length[Select[flist, Intersection[ #, FactorInteger[n]]=={}&]]; AppendTo[alist, a]; AppendTo[flist, FactorInteger[a]], {n, 2, 500}]; Print[alist]  Owen Whitby, May 20 2008


CROSSREFS

Sequence in context: A076618 A116550 A283165 * A103634 A255046 A098596
Adjacent sequences: A116988 A116989 A116990 * A116992 A116993 A116994


KEYWORD

nonn


AUTHOR

Leroy Quet, Apr 02 2006


EXTENSIONS

More terms from Owen Whitby, May 20 2008


STATUS

approved



