OFFSET
1,1
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..8160
EXAMPLE
61 is in the sequence because it is prime and the concatenation[ 61 with (6 + 1)] = 617 is also prime.
197 is in the sequence because it is prime and the concatenation[ 197 with (1 + 9 + 7)] = 19717 is also prime.
MAPLE
PROG
(PARI)
for(n=1, 10^3, p=prime(n); if(isprime(eval(concat(Str(p), Str(sumdigits(p))))), print1(p, ", "))) \\ Derek Orr, Jul 31 2014
CROSSREFS
KEYWORD
nonn,base
AUTHOR
K. D. Bajpai, Jul 31 2014
STATUS
approved