OFFSET
1,1
LINKS
Paolo P. Lava, Table of n, a(n) for n = 1..150
EXAMPLE
a(1) = 23 because 23^1 = 23 = concat(2,3);
a(2) = 5 because 5^2 = 25 = concat(2,5);
a(3) = 3 because 3^3 = 27 = concat(2,7).
MAPLE
with(numtheory): P:= proc(q) local a, k, n, ok;
for n from 1 to q do for a from 1 by 2 to q do if isprime(a) then ok:=0;
for k from 1 to ilog10(a^n) do if isprime(trunc(a^n/10^k)) and isprime(a^n mod 10^k) then ok:=1; break; fi; od; if ok=1 then print(a); break; fi; fi; od; od; end: P(10^9);
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Paolo P. Lava, Feb 16 2017
STATUS
approved