OFFSET
0,1
COMMENTS
The corresponding indices of a(n) in A246655 are 1, 3, 12, 240, ...
LINKS
Eric Weisstein's World of Mathematics, Prime Power
EXAMPLE
a(1) = 4 because 1/2 + 1/3 = 0.8333... < 1 but 1/2 + 1/3 + 1/4 = 1.0833... > 1.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Ilya Gutkovskiy, Mar 05 2020
EXTENSIONS
a(4) from Daniel Suteu, Mar 05 2020
STATUS
approved