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A162880
Numbers k such that tau(sigma(k)) is not equal to sigma(tau(k)).
1
2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 45, 46, 47, 48, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 67, 69, 71, 72, 73, 74, 75, 77, 78, 79, 80
OFFSET
1,1
COMMENTS
The complement of A076361, that is, the indices k where A076360(k) is not zero.
EXAMPLE
a(6)= 8 is in the list because tau(sigma(8))=A062068(8)=4 whereas sigma(tau(8)) = A062069(8) = 7.
PROG
(PARI) is(n)=numdiv(sigma(n))!=sigma(numdiv(n)) \\ Charles R Greathouse IV, Jun 25 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Jul 16 2009
EXTENSIONS
Edited by R. J. Mathar, Jul 21 2009
STATUS
approved