A195377 2.5-gap primes: Prime p is a term if there is no prime between 2.5*p and 2.5*q, where q is the next prime after p.

127, 197, 281, 311, 347, 431, 613, 659, 673, 739, 877, 991, 1049, 1229, 1277, 1289, 1367, 1481, 1579, 1613, 1667, 1721, 1787, 1877, 1907, 2027, 2081, 2087, 2141, 2203, 2213, 2237, 2239, 2269, 2287, 2309, 2377, 2383, 2473, 2657, 2689, 2707, 2749, 2767, 2801

Offset

1,1

Links

Table of n, a(n) for n=1..45.

Mathematica

Select[Prime[Range[500]], PrimePi[5*NextPrime[#]/2] == PrimePi[5*#/2] &] (* T. D. Noe, Sep 20 2011 *)

Crossrefs

Cf. A195270, A195271, A195325, A194658, A164294.

Sequence in context: A107380 A282793 A180539 * A142090 A095730 A325078

Adjacent sequences: A195374 A195375 A195376 * A195378 A195379 A195380

Keyword

nonn

Author

Vladimir Shevelev, Sep 17 2011

Status

approved