|
%I
%S 5,7,11,17,23,41,47,71,83,101,107,113,131,167,197,227,233,281,311,317,
%T 353,383,401,443,461,467,491,503,617,647,677,743,761,773,827,857,863,
%U 881,887,911,941,971,1013,1091,1097,1217,1283,1301,1307,1427,1433,1451
%N Primes n such that sigma(n-4) < n.
%C Except for the first term, members are primes of the form p+4 with p prime, i.e. the sequence is essentially A031505, A046132. In other words the solutions to sigma(x)<x+4 are 1,2,4 and the odd primes. - R. Stephan, Feb 09 2004
%Y Cf. A025584, A046022.
%K nonn,easy
%O 1,1
%A _Benoit Cloitre_, Feb 08 2002
%E Edited by _Charles R Greathouse IV_, Mar 19 2010
|