A069175 Numbers k such that k-1, k+1, 2*k-1, 2*k+1, 4*k-1 and 4*k+1 are all prime.

211050, 248640, 253680, 410340, 507360, 605640, 1121190, 1138830, 1262100, 2162580, 2172870, 2277660, 4070220, 6305460, 7671510, 11659410, 12577110, 14203770, 14862120, 17472840, 18728640, 18798360, 20520570, 21140700

Offset

1,1

Links

Table of n, a(n) for n=1..24.

Example

211050 is in the sequence because 211049, 211051, 422099, 422101, 844199 and 844201 are all prime.

Maple

isA069175 := proc(k)
    if isprime(k-1) and isprime(k+1) and isprime(2*k-1) and isprime(2*k+1) and isprime(4*k-1) and isprime(4*k+1) then
        true ;
    else
        false;
    end if;
end proc:
n := 1 :
for k from 4 by 2 do # create b-file
    if isA069175(k) then
        printf("%d %d\n", n, k) ;
        n := n+1 ;
    end if;
end do: # R. J. Mathar, Nov 02 2023

Mathematica

lst={}; Do[If[PrimeQ[n-1]&&PrimeQ[n+1]&&PrimeQ[2*n-1]&&PrimeQ[2*n+1]&&PrimeQ[4*n-1]&&PrimeQ[4*n+1], Print[n]; AppendTo[lst, n]], {n, 11!}]; lst (* Vladimir Joseph Stephan Orlovsky, Jan 05 2009 *)

Crossrefs

Cf. A066388.

Sequence in context: A172825 A072760 A178421 * A340158 A097021 A236086

Adjacent sequences: A069172 A069173 A069174 * A069176 A069177 A069178

Keyword

nonn

Author

Don Reble, Apr 09 2002

Extensions

Offset changed to 1 by Georg Fischer, Sep 23 2022

Status

approved