OFFSET
1,1
COMMENTS
a(18) > 10^13. - Giovanni Resta, Oct 19 2013
EXAMPLE
1757 is a 4-digit term since sequence is 1, 7, 5, 7, 1*7*5+7 =42, 7*5*7+42 = 287, 5*7*42+287 = 1757.
CROSSREFS
KEYWORD
nonn,base,more
AUTHOR
EXTENSIONS
a(15)-a(17) from Giovanni Resta, Oct 19 2013
STATUS
approved