This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A118859 #31 Mar 13 2025 05:16:10
%S A118859 6,53550,420420,422310,1624350,2130240,3399900,5199810,5246010,
%T A118859 6549270,7384440,7775880,9516570,9565710,10430280,11845260,13207950,
%U A118859 14562870,14619990,18747960,20099940,21596820,21968100,24358950,24610740,26916120,28359240,30838080
%N A118859 Numbers k such that k-1, k+1, 2*k-1, 2*k+1, 3*k-1 and 3*k+1 are primes.
%H A118859 Amiram Eldar, <a href="/A118859/b118859.txt">Table of n, a(n) for n = 1..4000</a>
%F A118859 a(n) = 6*A290811(n).
%e A118859 6 is a term because 5, 7, 11, 13, 17, 19 are all prime.
%t A118859 Select[Range[25*10^6],AllTrue[Flatten[{#+{1,-1},2#+{1,-1},3#+{1,-1}}], PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Sep 13 2016 *)
%o A118859 (PARI) isok(k) = isprime(k-1) && isprime(k+1) && isprime(2*k-1) && isprime(2*k+1) && isprime(3*k-1) && isprime(3*k+1); \\ _Amiram Eldar_, Mar 13 2025
%Y A118859 Subsequence of A014574 and A066388.
%Y A118859 Subsequences: A118860, A349321.
%Y A118859 Cf. A014574, A290811, A348348.
%K A118859 nonn
%O A118859 1,1
%A A118859 _Labos Elemer_, May 03 2006
%E A118859 Edited by _Don Reble_, May 16 2006
%E A118859 a(26)-a(28) from _Jon E. Schoenfield_, Dec 07 2021