OFFSET
1,1
COMMENTS
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..20000
PROG
(PARI) listap(nn) = {forstep(n=2, nn, 2, m = sigma(n)-n; if ((m > n) && (n==sigma(m)-m), print1(n, ", ", m, ", ")); ); } \\ Michel Marcus, Nov 14 2015
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Omar E. Pol, Nov 09 2015
STATUS
approved