OFFSET
1,1
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..7200
EXAMPLE
a(3)= 163: prime(6)^2 - 6= 13^2 - 6= 169 - 6= 163 which is prime.
a(4)= 353: prime(8)^2 - 8= 19^2 - 8= 361 - 8= 353 which is prime.
MAPLE
with(numtheory):KD := proc() local a; a:= (ithprime(k)^2-k); if isprime(a) then RETURN (a); fi; end: seq(KD(), k=1..1000);
MATHEMATICA
Select[Table[Prime[k]^2-k, {k, 1000}], PrimeQ]
PROG
(PARI) for(k=1, 10^5, if(ispseudoprime(KD=((prime(k)^2-k))), print1(KD", ")));
CROSSREFS
KEYWORD
nonn
AUTHOR
K. D. Bajpai, Oct 26 2013
STATUS
approved