

A175107


a(1)=1. For n >= 2, if A025474(n) is the exponent of the nth primepower (1 is considered the first primepower here), then a(n) = the A025474(n)th integer from among those positive integers not yet in the sequence.


0



1, 2, 3, 5, 4, 6, 9, 8, 7, 10, 14, 11, 12, 13, 16, 18, 15, 17, 23, 19, 20, 21, 22, 25, 24, 26, 27, 33, 28, 29, 30, 31, 36, 32, 34, 35, 37, 38, 39, 40, 41, 43, 45, 42, 51, 44, 46, 47, 48, 49, 50, 52, 53, 55, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 73, 69, 78, 70
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OFFSET

1,2


COMMENTS

This sequence is a permutation of the positive integers.


LINKS

Table of n, a(n) for n=1..72.


EXAMPLE

9 is the 8th power of a prime. 9 = 3^2. So we want the 2nd integer (because 2 is the exponent) from among those positive integers not in the first 7 terms of the sequence. The first 7 terms are 1,2,3,5,4,6, 9. Those positive integers not yet appearing form the infinite sequence 7,8,10,11,12,13,14,15,16... The 2nd integer not yet occurring is 8. So a(9)=8.


CROSSREFS

Cf. A025474.
Sequence in context: A279344 A316669 A185180 * A085181 A268129 A185725
Adjacent sequences: A175104 A175105 A175106 * A175108 A175109 A175110


KEYWORD

nonn


AUTHOR

Leroy Quet, Feb 11 2010


EXTENSIONS

Extended by Ray Chandler, Mar 10 2010


STATUS

approved



