(MAGMAMagma) [n: n in [1..1000] | n-1 eq ((n*(n+1) div 2-SumOfDivisors(n)) mod n)]. // Jaroslav Krizek, May 28 2014
OEIS Server: https://oeis.org/edit/global/2944
editing
approved
Union of A065091 (odd primes) and sequence non-primesnonprimes 1, 4, 36, ... (all terms < 10^5).
No more composite terms to 10^910. - Charles R Greathouse IV, Nov 02 2014
No more composite terms to 10^9. - Charles R Greathouse IV, Nov 02 2014
(PARI) is(n)=(n*(n+1)/2-sigma(n)+1)%n==0 \\ Charles R Greathouse IV, Nov 02 2014
(MAGMA) [n: n in [1..1000] | n-1 eq ((n*(n+1)) div 2-SumOfDivisors(n)) mod n)]. // Jaroslav Krizek, May 28 2014
proposed
