OFFSET
1,1
LINKS
K. D. Bajpai, Table of n, a(n) for n = 1..6700
EXAMPLE
a(3) = 53 : prime(4)^2 + 4 = 7^2 + 4 = 49 + 4 = 53 which is prime.
a(4) = 1381 : prime(12)^2 + 12 = 37^2 + 12 = 1369 + 12 = 1381 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 24 2013
STATUS
approved