1,1

The primes following a(5) and a(6) occur at a(n)+30*k, k=0..(n-1). a(6) was found by Lander and Parkin. The next term requires a spacing >=210. The expected size is a(7)>10^21 (see link). - Hugo Pfoertner (hugo(AT)pfoertner.org), Jun 25 2004

Starting (1, 20, 84, 220,...) = binomial transform of (1, 19, 45, 27, 0, 0, 0,...).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

L. J. Lander and T. R. Parkin, Consecutive Primes in Arithmetic Progression. Math. Comput. 21, 489, 1967.

Jens Kruse Andersen, The smallest known CPAP-k.

Index entries for sequences related to primes in arithmetic progressions

More terms from Gary W. Adamson (qntmpkt(AT)yahoo.com), Apr 22 2008

a(4)=251: 251,257,263,269 is the first occurrence of 4 consecutive primes in arithmetic progression.

Cf. A005115, A093364, A126989.

Sequence in context: A083113 A027498 A094877 this_sequence A088251 A140839 A127528

Adjacent sequences: A006557 A006558 A006559 this_sequence A006561 A006562 A006563

nonn,hard

N. J. A. Sloane (njas(AT)research.att.com).