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 A175074 #4 Jun 27 2020 11:42:28
%S A175074 1,4,6,8,10,12,14,16,18,20,22,24,26,27,30,32,34,35,38,40,42,44,46,48,
%T A175074 50,51,54,56,57,60,62,64,65,68,70,72,74,76,77,80,82,84,86,87,90,92,93,
%U A175074 95,98,100,102
%N A175074 Nonprimes b with result 1 under iterations of {r mod (max prime p < r)} starting at r = b.
%C A175074 Subsequence of A175071. Union of a(n) and A175073 is A175071.
%C A175074 Union of a(n) and A175073 is A175071. [From _Jaroslav Krizek_, Jan 30 2010]
%e A175074 Iteration procedure for a(5) = 10: 10 mod 7 = 3, 3 mod 2 = 1.
%t A175074 np1Q[n_]:=!PrimeQ[n]&&MemberQ[NestWhileList[Mod[#,NextPrime[#,-1]]&,n,#>0&],1]; Select[Range[150],np1Q] (* _Harvey P. Dale_, Jun 27 2020 *)
%K A175074 nonn
%O A175074 1,2
%A A175074 _Jaroslav Krizek_, Jan 23 2010