A086801 a(n) = prime(n) - 3.

-1, 0, 2, 4, 8, 10, 14, 16, 20, 26, 28, 34, 38, 40, 44, 50, 56, 58, 64, 68, 70, 76, 80, 86, 94, 98, 100, 104, 106, 110, 124, 128, 134, 136, 146, 148, 154, 160, 164, 170, 176, 178, 188, 190, 194, 196, 208, 220, 224, 226, 230, 236, 238, 248, 254, 260, 266, 268, 274, 278

Offset: 1

Author

Giovanni Teofilatto, Aug 05 2003

Keywords

• easy
• sign

Comments

Numbers n such that n+3 is a prime.

Examples

			n=16 is here because 16+3=19 is a prime.
		

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

Crossrefs

Cf. A006254, A067076, A091738, A116127, A119981, A173064.

Programs

Mathematica

Prime[Range[22]]-3 (* Vladimir Joseph Stephan Orlovsky, Apr 29 2008 *)

PARI

for(x=2,20,print1(prime(x)-3,",")) \\ Jorge Coveiro, Jan 30 2006

Formula

a(n) = 2*A067076(n) = 2*(A006254(n+1)-2).

Extensions

Extended by Ray Chandler, Nov 29 2003