A089253 Numbers n such that 2n - 5 is a prime.

4, 5, 6, 8, 9, 11, 12, 14, 17, 18, 21, 23, 24, 26, 29, 32, 33, 36, 38, 39, 42, 44, 47, 51, 53, 54, 56, 57, 59, 66, 68, 71, 72, 77, 78, 81, 84, 86, 89, 92, 93, 98, 99, 101, 102, 108, 114, 116, 117, 119, 122, 123, 128, 131, 134, 137, 138, 141, 143, 144, 149, 156, 158, 159, 161

Offset

1,1

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

Shawn A. Broyles, Table of n, a(n) for n = 1..1000

Formula

a(n) = A067076(n) + 4. - Giovanni Teofilatto, Dec 14 2003

Mathematica

(Prime[Range[2, 100]]+5)/2 (* Vladimir Joseph Stephan Orlovsky, Feb 08 2010 *)

Prog

(PARI) a(n)=prime(n+1)\2+3 \\ Charles R Greathouse IV, Oct 30 2012

Crossrefs

Numbers n such that 2n+k is prime: A005097 (k=1), A067076 (k=3), A089038 (k=5), A105760 (k=7), A155722 (k=9), A101448 (k=11), A153081 (k=13), A089559 (k=15), A173059 (k=17), A153143 (k=19).

Numbers n such that 2n-k is prime: A006254 (k=1), A098090 (k=3), this sequence (k=5), A089192 (k=7), A097069 (k=9), A097338 (k=11), A097363 (k=13), A097480 (k=15), A098605 (k=17), A097932 (k=19).

Sequence in context: A091242 A354834 A089585 * A047432 A095279 A030751

Adjacent sequences: A089250 A089251 A089252 * A089254 A089255 A089256

Keyword

easy,nonn

Author

Giovanni Teofilatto, Dec 12 2003

Extensions

Corrected by Ralf Stephan, Mar 03 2004

Further correction from Jeremy Gardiner, Sep 11 2004

Status

approved