OFFSET
1,1
COMMENTS
The values corresponding to a(1)-a(6) have been certified prime with Primo. a(7) > 15000. - Giovanni Resta, Feb 20 2013
MATHEMATICA
f[n_] := n!/10^Sum[Floor[n/5^k], {k, 1, Log[10, n] + 1}]; Do[ If[ PrimeQ[ FromDigits[ Reverse[ IntegerDigits[ f[n]]]] - 1], Print[n]], {n, 1, 800}]
CROSSREFS
KEYWORD
base,more,nonn
AUTHOR
Jason Earls and Robert G. Wilson v, Dec 27 2002
EXTENSIONS
a(6) from Giovanni Resta, Feb 20 2013
STATUS
approved