OFFSET
1,2
COMMENTS
A zero digit raised to the zeroth power is treated as equaling one. - Harvey P. Dale, Feb 19 2013
LINKS
Eric M. Schmidt, Table of n, a(n) for n = 1..1000
EXAMPLE
a(7)=35 because 35*(3^3 + 5^5) + 1 = 110321 is prime.
MATHEMATICA
ndnQ[n_]:=Module[{idn=IntegerDigits[n]/.{0->1}}, PrimeQ[n*Total[idn^idn]+1]]; Select[Range[500], ndnQ] (* Harvey P. Dale, Feb 19 2013 *)
PROG
(PARI) isok(n) = my(d = digits(n)); isprime(n*sum(i=1, #d, d[i]^d[i])+1); \\ Michel Marcus, Sep 16 2018
CROSSREFS
KEYWORD
base,easy,nonn
AUTHOR
Jason Earls, Aug 24 2005
STATUS
approved