OFFSET
1,2
COMMENTS
No other terms below 10^15. A larger term: 9135884036634915191945452485106476242. - Max Alekseyev, Oct 12 2016
Terms are not divisible by 127 (Alekseyev 2016).
REFERENCES
M. A. Alekseyev. "Problem 4101". Crux Mathematicorum 42:1 (2016), 28.
EXAMPLE
3 == 7 mod 1, so 1 is a term;
9 == 7 mod 2, so 2 is a term.
PROG
(PARI) isok(n) = Mod(3, n)^n == 7; \\ Michel Marcus, Oct 06 2016
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Seiichi Manyama, Oct 06 2016
EXTENSIONS
a(5) from Joerg Arndt, Oct 06 2016
a(6)-a(11) from Max Alekseyev, Oct 12 2016
STATUS
approved