OFFSET
1,2
COMMENTS
LINKS
Eric Weisstein's World of Mathematics, Generalized Fermat Number
EXAMPLE
A080121 begins with 1,1,2,1,1,2,1,2,1,5,?,1,2,1,?,2,1,?,1,?,4,1,3,1,..., where the unknown terms (denoted with ?) are at least 10. So a(1) = 1, a(2) = 3, a(3) = 23, a(4) = 21, a(5) = 10.
CROSSREFS
KEYWORD
hard,more,nonn
AUTHOR
Alexander Adamchuk, Sep 18 2006, Oct 01 2006
EXTENSIONS
Edited by Max Alekseyev, Sep 09 2020
STATUS
approved