A089953 Numbers n such that 3*n+7 is prime.

0, 2, 4, 8, 10, 12, 18, 20, 22, 24, 30, 32, 34, 40, 44, 48, 50, 52, 58, 62, 64, 68, 72, 74, 78, 88, 90, 92, 100, 102, 108, 110, 114, 120, 122, 124, 130, 134, 138, 142, 144, 150, 152, 160, 164, 172, 178, 180, 188, 190, 198, 200, 202, 204, 208, 212, 218, 222, 228

Offset: 1

Author

Giovanni Teofilatto, Jan 12 2004

Keywords

• nonn

References

• M. Cerasoli, F. Eugeni and M. Protasi, Elementi di Matematica Discreta, Bologna 1988.
• Emanuele Munarini and Norma Zagaglia Salvi, Matematica Discreta,UTET, CittaStudiEdizioni, Milano 1997.

Links

• Daniel Starodubtsev, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A002476 gives primes, A034936, A024892, A024899.

Programs

PARI

is(n)=isprime(3*n+7) \\ Charles R Greathouse IV, May 22 2017

Formula

a(n) = A034936(n)-1 = A024892(n)-2 = 2*A024899(n)-2.

Extensions

Offset corrected by Arkadiusz Wesolowski, Aug 09 2011