OFFSET
1,1
COMMENTS
The number g may be negative.
g is always 0 mod 6 so a multiple of 6.
LINKS
Pierre CAMI, Table of n, a(n) for n = 1..390
EXAMPLE
135*2^1-1=269, 135*2^1-1-6=263, 135*2^1-1-2*6=257, 135*2^1-1-3*6=251
269, 263, 257, 251 are four consecutive primes in arithmetic progression so a(1)=135, a(2)=-6.
63*2^2-1=251, 63*2^2-1+6=257, 63*2^2-1+2*6=263, 63*2^2-1-3*6=269
251, 257, 263, 269 are four consecutive primes in arithmetic progression so a(3)=63 a(4)=6.
CROSSREFS
KEYWORD
sign
AUTHOR
Pierre CAMI, Oct 30 2013
STATUS
approved