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

1,1

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.

Links

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

Example

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

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]

Crossrefs

Cf. A048880.

Sequence in context: A142662 A178416 A182477 * A107215 A142142 A265915

Adjacent sequences: A229567 A229568 A229569 * A229571 A229572 A229573

Keyword

nonn

Author

K. D. Bajpai, Sep 26 2013

Status

approved