A088429 Number of primes in arithmetic progression starting with 31 and with d=2n.

1, 1, 3, 1, 2, 2, 1, 2, 1, 1, 2, 1, 1, 2, 2, 1, 1, 4, 1, 2, 2, 1, 1, 3, 1, 2, 1, 1, 2, 1, 1, 1, 4, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 1, 1, 1, 1, 3, 1, 2, 1, 1, 2, 2, 1, 1, 1, 1, 2, 3, 1, 1, 4, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 1, 2, 2, 1, 2, 3, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 2, 1

Offset

1,3

Comments

Arithmetic progression is stopped when next term is not prime. E.g. for n=3 (d=6), a=3, that is 31,37,43 are prime, while next term, 49, is not prime.

Links

Table of n, a(n) for n=1..100.

Mathematica

bb={}; Do[s=1; Do[If[PrimeQ[31+k*d], s=s+1, bb={bb, s}; Break[]], {k, 10}], {d, 2, 200, 2}]; Flatten[bb]

Crossrefs

Cf. A088420, A088421, A088422, A088423, A088424, A088425, A088426, A088427, A088428.

Sequence in context: A056529 A087282 A105973 * A134658 A296518 A111951

Adjacent sequences: A088426 A088427 A088428 * A088430 A088431 A088432

Keyword

easy,nonn

Author

Zak Seidov, Sep 29 2003

Status

approved