The On-Line Encyclopedia of Integer Sequences (OEIS)

A066081 revision #12

A066081

a(n) = smallest m such that m+2^j and m-2^j are prime for all 0 < j <= n.

5, 9, 15, 50943795, 40874929095, 616517522595975, 93487500801880185, 64606701602327559675

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

Is this sequence infinite?

LINKS

EXAMPLE

9-4, 9-2, 9+2, 9+4 are prime, but not 5+4 = 7+2, therefore a(2) = 9.

CROSSREFS

Prime quadruples: A014561, sextets: A061671, octets: A066082.

KEYWORD

hard,nonn

AUTHOR

EXTENSIONS

a(5) and a(6) from Don Reble, Dec 07 2001

a(7) from Jim Fougeron (Feb 07) confirmed by Phil Carmody, who also found a(8) (Feb 14 2002).

STATUS

approved