OFFSET
1,1
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
MATHEMATICA
Table[s = Prime[n]; While[s >= 10, s = Times @@ IntegerDigits[s]]; s, {n, 100}] (* T. D. Noe, Nov 15 2011 *)
Table[NestWhile[Times@@IntegerDigits[#]&, p, #>9&], {p, Prime[Range[90]]}] (* Harvey P. Dale, Jul 31 2020 *)
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, Nov 13 2011
STATUS
approved