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URL: https://oeis.org/A147569

⇱ A147569 - OEIS

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A147569
a(n) = sigma(A020492(n)).
2
1, 3, 4, 12, 28, 24, 24, 72, 48, 96, 120, 144, 168, 192, 336, 480, 360, 576, 480, 720, 720, 576, 720, 1344, 1440, 1440, 1440, 1872, 1728, 1920, 1680, 2880, 2016, 1440, 2880, 2880, 2880, 3600, 5760, 4320, 5040, 7200, 6720, 7392, 8064, 8640, 8640, 5760, 5616
OFFSET
1,2
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (calculated from the b-file at A020492)
EXAMPLE
a(5) = sigma(A020492(5)) = sigma(12) = 28.
PROG
(Magma) [ SumOfDivisors(n): n in [1..3500] | SumOfDivisors(n) mod EulerPhi(n) eq 0 ]; // Klaus Brockhaus, Nov 09 2008
(PARI) {for(n=1, 3500, a=sigma(n); if(a%eulerphi(n)==0, print1(a, ", ")))} \\ Klaus Brockhaus, Nov 09 2008
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Enoch Haga, Nov 07 2008
EXTENSIONS
Edited by Klaus Brockhaus, Nov 09 2008
STATUS
approved