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

Author

Pierre CAMI, Oct 26 2013

Keywords

• nonn

Examples

			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.
		

Links

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

Crossrefs

Cf. A052187.