OFFSET
1,2
COMMENTS
a(n) = the largest n-digit number of the form p^6 (p = prime), a(n) = 0 if no such number exists.
FORMULA
A000005(a(n)) = 7.
MATHEMATICA
Table[p=Floor[10^(n/6)]; While[p^6>10^(n-1) && ! PrimeQ[p], p = NextPrime[p, -1]]; If[p^6>10^(n-1), p^6, 0], {n, 20}]
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, Nov 27 2010
STATUS
approved