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

1,1

Comments

The union of sequences A069456 and A227063.

Prime(k) such that prime(k-i), i=1..3, and prime(k+i), i=1..3 are in A001097.

Links

Table of n, a(n) for n=1..32.

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

Crossrefs

Sequence in context: A046187 A234634 A004811 * A126197 A355546 A090814

Adjacent sequences: A227320 A227321 A227322 * A227324 A227325 A227326

Keyword

nonn

Author

Irina Gerasimova, Jul 06 2013

Extensions

Corrected by R. J. Mathar, Jul 13 2013

Status

approved