A227323 Prime(k) such that each of the three preceding and also each of the three following primes are twin primes.
11, 1039, 2099, 4253, 9433, 9437, 62983, 62987, 72229, 72251, 91121, 386401, 392269, 392279, 495589, 495611, 626617, 663583, 663587, 754973, 873553, 908857, 909301, 909317, 909319, 909329, 972137, 1006309, 1006331, 1138393, 1138409, 1159201
Offset: 1
Keywords
Programs
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Maple
istwp := proc(n) if isprime(n) then if isprime(n+2) or isprime(n-2) then true; else false; end if; else false; end if; end proc: for i from 4 do p := ithprime(i) ; p1 := prevprime(p) ; if istwp(p1) then p2 := prevprime(p1) ; if istwp(p2) then p3 := prevprime(p2) ; if istwp(p3) then p1 := nextprime(p) ; if istwp(p1) then p2 := nextprime(p1) ; if istwp(p2) then p3 := nextprime(p2) ; if istwp(p3) then printf("%d\n",p) ; end if; end if; end if; end if; end if; end if; end do: # R. J. Mathar, Jul 13 2013
Extensions
Corrected by R. J. Mathar, Jul 13 2013
Comments