A090696 Numbers k such that k^2 - 11 is a prime.

4, 8, 10, 18, 20, 28, 32, 38, 42, 48, 52, 62, 70, 78, 80, 90, 118, 120, 130, 148, 158, 160, 172, 182, 200, 210, 218, 228, 230, 232, 238, 248, 252, 258, 260, 262, 270, 272, 290, 298, 300, 302, 318, 340, 342, 350, 358, 360, 370, 372, 378, 388, 398, 410, 412, 420

Offset: 1

Author

Giovanni Teofilatto, Dec 20 2003

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..5000

Crossrefs

A091272 gives primes, A091273 gives prime index.

Programs

Mathematica

Select[Range[4,1200],PrimeQ[#^2-11]&] (* Vladimir Joseph Stephan Orlovsky, Feb 27 2011*)

Formula

a(n) = 2*A091271(n).

Extensions

Extended by Ray Chandler, Dec 27 2003