OFFSET
1,2
COMMENTS
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
select(t -> isprime(t+numtheory:-sigma(t)), [$1..1000]); # Robert Israel, May 01 2018
MATHEMATICA
Select[Range[10^3], PrimeQ[ # + DivisorSigma[1, # ]] &]
PROG
(PARI) for(n=1, 1000, if(isprime(sigma(n)+n), print1(n, ", "))) \\ Derek Orr, Nov 13 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Joseph L. Pe, Jan 08 2003
STATUS
approved