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Composite n such that n reduced mod(phi(n)) = sigma(n) reduced mod(n).
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%I #9 Jan 13 2017 14:53:55

%S 6,56,260,780,992,1976,2156,3696,5520,13800,16256,19872,22560,23688,

%T 25232,41072,87000,89964,133984,145888,366720,785808,851760,1100864,

%U 1235052,1270208,1439552,1470720,2129400,2237888,4729664,8690112

%N Composite n such that n reduced mod(phi(n)) = sigma(n) reduced mod(n).

%C Are all terms even? - _Robert Israel_, Jan 13 2017

%p select(n -> not isprime(n) and n mod numtheory:-phi(n) = numtheory:-sigma(n) mod n, [$2..10^7]); # _Robert Israel_, Jan 13 2017

%o (PARI) for(n=3,500000, if(n%eulerphi(n)==(1-isprime(n))*sigma(n)%n,print1(n,",")))

%Y Contains A139256(n) for n > 1.

%K easy,nonn

%O 1,1

%A _Benoit Cloitre_, Mar 11 2002

%E a(31) and a(32) from _Robert Israel_, Jan 13 2017