A142345 Primes of the form (p(n)+r(n))/3, where p(n) = n-th prime and r(n) = n-th nonprime.

3, 23, 29, 37, 41, 47, 61, 67, 83, 103, 113, 149, 157, 167, 193, 269, 277, 281, 331, 347, 439, 521, 569, 593, 677, 733, 823, 827, 877, 911, 1019, 1061, 1097, 1117, 1153, 1217, 1259, 1289, 1381, 1433, 1447, 1489, 1499, 1553, 1607, 1637, 1693, 1699, 1733, 1801

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

If n=3, then (p(3)+r(3))/3 = (5+4)/3 = 3 = a(1).
If n=15, then (p(15)+r(15))/3 = (47+22)/3 = 23 = a(2).
If n=18, then (p(18)+r(18))/3 = (61+26)/3 = 29 = a(3).
If n=22, then (p(22)+r(22))/3 = (79+32)/3 = 37 = a(4).
If n=24, then (p(24)+r(24))/3 = (89+34)/3 = 41 = a(5), etc.

Mathematica

Module[{nn=5000, pr, comp, len}, pr=Prime[Range[PrimePi[nn]]]; comp = Complement[ Range[0, nn], pr]; len = Min[ Length[pr], Length[comp]]; Select[Total[#]/3&/@Thread[ {Take[pr, len], Take[comp, len]}], PrimeQ]] (* Harvey P. Dale, Dec 04 2012 *)

Crossrefs

Cf. A000040, A141468.

Sequence in context: A103361 A136090 A032688 * A371980 A217329 A133023

Adjacent sequences: A142342 A142343 A142344 * A142346 A142347 A142348

Keyword

nonn

Author

Juri-Stepan Gerasimov, Sep 19 2008

Extensions

167 inserted, 347 inserted and extended by R. J. Mathar, Nov 03 2008

Status

approved