OFFSET
1,1
COMMENTS
Here s(k) = sigma(k) - k (see A001065).
a(10) > 10^10, if it exists. - Amiram Eldar, Mar 14 2024
PROG
(PARI) s(n) = sigma(n) - n;
is(n) = {my(s1 = s(n)); if(s1 >= n, 0, n - s1 - s(n-s1) == s(s1) - s1); } \\ Amiram Eldar, Mar 14 2024
CROSSREFS
KEYWORD
nonn,more
AUTHOR
EXTENSIONS
More terms from Jason Earls, Aug 30 2001
Offset corrected, wrong term removed and a(8)-a(9) added by Amiram Eldar, Mar 14 2024
STATUS
approved