OFFSET
0,5
LINKS
Eric Weisstein's World of Mathematics, Perfect Power
FORMULA
a(p) = a(p-1) for p prime.
EXAMPLE
a(8) = 11 subsets: {}, {4}, {8}, {2, 4}, {2, 8}, {4, 8}, {2, 3, 6}, {2, 4, 8}, {3, 6, 8}, {2, 3, 4, 6} and {3, 4, 6, 8}.
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 08 2020
EXTENSIONS
a(25)-a(40) from Alois P. Heinz, Dec 08 2020
STATUS
approved