OFFSET
1,1
COMMENTS
LINKS
Eric Weisstein's World of Mathematics, Friendly Pair.
EXAMPLE
28/6 < 224/40 < 234/12 < 496/6 < 6200/30 < 8128/6 < 174592/40 < ....
PROG
(PARI) isrmax(i, rmax) = {si = sigma(i); if (gcd(si, i) == 1, return (0)); s = si/i; for (j=1, i\rmax, if ((sigma(j)/j) == s, if ((newr = i/j) > rmax, return (newr)); ); ); return (0); }
lista(nn) = {rmax = 1; for (i = 1, nn, if ((newr = isrmax(i, rmax)), rmax = newr; print1(i, ", "); ); ); }
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Michel Marcus, Jan 23 2014
STATUS
approved