A229570 Primes of form p*q + 30, where p and q are consecutive primes.

107, 173, 251, 353, 467, 929, 2521, 4787, 7417, 8663, 10433, 12347, 17977, 19073, 25621, 28921, 32429, 39233, 42019, 50651, 55717, 60521, 77867, 95507, 97373, 99251, 111577, 116969, 126757, 131783, 141397, 159227, 164039, 171401, 186653, 194507, 198937, 205223

Offset: 1

Author

K. D. Bajpai, Sep 26 2013

Keywords

• nonn

Comments

Conjecture: The expression p*q + c with p and q consecutive primes and c = 30 generates more primes than any other value of c in the range 1 < c < 100 and p = 48611 which is 5000th prime. Hence, c = 30 is considered for this sequence.

Examples

			a(1)=107: prime(4)*prime(5)+30=107, which is prime.
a(6)=929: prime(10)*prime(11)+30=929, which is prime.
		

Links

• K. D. Bajpai, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A048880.

Programs

Maple

KD:= proc() local a; a:= ithprime(n)*ithprime(n+1)+30; if isprime((a)) then RETURN((a)):fi;end: seq(KD(),n=1..500);

Mathematica

Select[Table[Prime[n]*Prime[n+1]+30,{n,100}],PrimeQ]