OFFSET
1,1
COMMENTS
a(n) is odd for all n.
EXAMPLE
17117217317417517617717817917 is prime. Thus, 17 is a member of this sequence.
PROG
(PARI) for(n=1, 10^4, b=""; for(i=2, 20, if(i==Mod(1, 2), b=concat(b, Str((i-1)/2))); if(i==Mod(0, 2), b=concat(b, Str(n)))); if(ispseudoprime(eval(b)), print1(n, ", ")))
CROSSREFS
KEYWORD
nonn,base,less
AUTHOR
Derek Orr, Jun 24 2014
STATUS
approved