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 A171696 #23 Jul 10 2025 08:14:20
%S A171696 0,20,24,31,34,36,41,48,50,54,57,69,71,79,86,88,89,92,97,104,106,111,
%T A171696 116,119,130,132,134,136,139,141,145,149,150,154,160,167,171,174,176,
%U A171696 179,180,189,190,191,193,196,201,207,209,211,212,219,222,223,224,225
%N A171696 Nonnegative numbers k such that neither of 6*k +- 1 is prime.
%C A171696 A060461 is the main sequence for this entry.
%H A171696 Amiram Eldar, <a href="/A171696/b171696.txt">Table of n, a(n) for n = 1..10000</a>
%F A171696 a(n+1) = A060461(n).
%F A171696 a(n) = n + O(n/log n). - _Charles R Greathouse IV_, Feb 17 2017
%p A171696 isA171696 := proc(n) not isprime(6*n+1) and not isprime(6*n-1) ; end proc: for n from 0 to 300 do if isA171696(n) then printf("%d,",n) ; end if; end do: # _R. J. Mathar_, Mar 18 2010
%t A171696 Select[Range[0, 225], !Or @@ PrimeQ[6# + {-1, 1}] &] (* _Amiram Eldar_, Jan 21 2020 *)
%o A171696 (PARI) is(n)=!isprime(6*n-1) && !isprime(6*n+1) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y A171696 Cf. A001477.
%Y A171696 The same as A060461, except for the initial 0.
%K A171696 nonn
%O A171696 1,2
%A A171696 _Juri-Stepan Gerasimov_, Dec 15 2009