A147569 a(n) = sigma(A020492(n)).

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

Cf. A020492, A023897, A147570.

Sequence in context: A330659 A000207 A002986 * A090660 A288140 A287594

Adjacent sequences: A147566 A147567 A147568 * A147570 A147571 A147572

Keyword

easy,nonn

Author

Enoch Haga, Nov 07 2008

Extensions

Edited by Klaus Brockhaus, Nov 09 2008

Status

approved