A099466 Numbers n such that 3*prime(n) + prime(n+1) - 3 is prime.

2, 3, 4, 5, 6, 7, 11, 12, 13, 14, 15, 19, 20, 22, 25, 30, 31, 33, 34, 36, 37, 38, 44, 45, 47, 49, 53, 55, 58, 59, 60, 63, 66, 67, 73, 79, 83, 87, 91, 93, 95, 98, 105, 107, 113, 115, 118, 122, 123, 127, 131, 135, 141, 144, 145, 147, 150, 153, 160, 162, 165, 167, 172, 177

Offset

1,1

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(2)=4 since 3*prime(4) + prime(5) - 3 = 3*7 + 11 - 3 = 29 is prime.

Maple

P:= select(isprime, [2, seq(i, i=3..10^4, 2)]):
select(n -> isprime(3*P[n]+P[n+1]-3), [$1..nops(P)-1]); # Robert Israel, Nov 29 2017

Crossrefs

Sequence in context: A214677 A275910 A032971 * A358673 A032976 A174219

Adjacent sequences: A099463 A099464 A099465 * A099467 A099468 A099469

Keyword

nonn

Author

Giovanni Teofilatto, Nov 18 2004

Extensions

Corrected and extended by Rick L. Shepherd, Nov 24 2004

Status

approved