A126555 Primes in A126554.

29, 1439, 4211, 7703, 12907, 14957, 16703, 20947, 29221, 31189, 33053, 36749, 44531, 51437, 90247, 115547, 124783, 127163, 133337, 144511, 146449, 151339, 157133, 166219, 169241, 180233, 181031, 185123, 197383, 223367, 225287, 240347

Offset

1,1

Comments

Primes that are the arithmetic mean of two consecutive balanced primes (of order one); primes of the form (A006562(k)+A006562(k+1))/2.

Might be called prime interprimes of order two.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Mathematica

b = {}; a = {}; Do[If[PrimeQ[((Prime[n + 2] + Prime[n + 1])/2 + (Prime[n + 1] + Prime[n])/2)/2], AppendTo[a, ((Prime[n + 2] + Prime[n + 1])/2 + (Prime[n + 1] + Prime[n])/2)/2]], {n, 1, 10000}]; Do[If[PrimeQ[(a[[k + 1]] + a[[k]])/2], AppendTo[b, (a[[k + 1]] + a[[k]])/2]], {k, 1, Length[a] - 1}]; b

Prog

(PARI) {m=250000; a=0; p=2; q=3; r=5; while(r<=m, if((p+r)/2==q, if(a>0, if(isprime(b=(a+q)/2), print1(b, ", "))); a=q); p=q; q=r; r=nextprime(r+1))} \\ Klaus Brockhaus, Jan 05 2007

Crossrefs

Cf. A126554, A006562.

Sequence in context: A191968 A049657 A091994 * A028478 A370679 A042627

Adjacent sequences: A126552 A126553 A126554 * A126556 A126557 A126558

Keyword

nonn

Author

Artur Jasinski, Dec 27 2006

Extensions

Edited and extended by Klaus Brockhaus, Jan 05 2007

Status

approved