A141863 Primes of the form n/(2*(p(n-1)-p(n-2))), where p(n)=n-th prime.

3, 2, 3, 7, 5, 2, 5, 11, 17, 7, 17, 59, 13, 17, 41, 23, 29, 61, 47, 199, 101, 71, 41, 23, 263, 269, 137, 139, 97, 59, 101, 103, 67, 173, 353, 127, 409, 139, 419, 449, 229, 163, 199, 103, 223, 229, 349, 181, 733, 751, 853, 883, 109, 197, 1033, 347, 521, 211, 137, 1109, 373

Offset

1,1

Links

Table of n, a(n) for n=1..61.

Example

n=12: 12/(2*(p(12-1)-p(12-2)))=12/(2*(31-29))=3=a(1).
n=16: 16/(2*(p(16-1)-p(16-2)))=16/(2*(47-43))=2=a(2).
n=24: 24/(2*(p(24-1)-p(24-2)))=24/(2*(83-79))=3=a(3).
n=28: 28/(2*(p(28-1)-p(28-2)))=28/(2*(103-101))=7=a(4).
n=40: 40/(2*(p(40-1)-p(40-2)))=40/(2*(167-163))=5=a(5).

Mathematica

Select[Table[n/(2(Prime[n-1]-Prime[n-2])), {n, 3, 5000}], PrimeQ] (* Harvey P. Dale, Jul 11 2012 *)

Crossrefs

Cf. A000040, A001223.

Sequence in context: A350770 A332057 A275330 * A071010 A343231 A215934

Adjacent sequences: A141860 A141861 A141862 * A141864 A141865 A141866

Keyword

nonn

Author

Juri-Stepan Gerasimov, Sep 15 2008

Extensions

Corrected and extended by R. J. Mathar, Sep 26 2008

Status

approved