A227888 Smallest odd k such that k*2^n-1, k*2^n-1+2*j, k*2^n-1+4*j or k*2^n-1-2*j, k*2^n-1, k*2^n-1+2*j are consecutive primes in arithmetic progression for some j.

3, 1, 19, 3, 19, 273, 93, 113, 87, 35, 31, 143, 31, 15, 315, 779, 207, 347, 91, 327, 291, 351, 195, 39, 1911, 971, 1083, 435, 1345, 593, 183, 1295, 291, 2553, 735, 1113, 31, 131, 61, 209, 379, 567, 2331, 1907, 4429, 23, 453, 1517, 2281, 2187, 1441, 4847, 1975

Offset

1,1

Links

Pierre CAMI, Table of n, a(n) for n = 1..325

Example

3*2^1-1-2=3 3*2^1-1=5 3*2^1-1+2=7 so a(1)=3.
3*2^4-1=47 3*2^4-1+6=53 3*2^4-1+12=59 so a(4)=3.

Crossrefs

Cf. A052187.

Sequence in context: A290317 A016480 A086156 * A188109 A247232 A147076

Adjacent sequences: A227885 A227886 A227887 * A227889 A227890 A227891

Keyword

nonn

Author

Pierre CAMI, Oct 26 2013

Status

approved