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 A109559 #5 Jun 03 2025 01:08:19
%S A109559 23,31,283,337,409,421,547,577,631,661,797,997,1201,1237,1307,1459,
%T A109559 1499,1511,1531,1583,1709,1789,1811,1889,2039,2357,2423,2633,2753,
%U A109559 2819,2939,3023,3593,3677,3779,3833,3863,4057,4111,4139,4493,4567,4621,4817,4889,4973
%N A109559 prime(k) for those k where floor((2*(prime(k+1)-prime(k))*PrimePi(k) mod (8*k))/k) = m with m = 5.
%t A109559 a = Flatten[Table[If[Floor[2*Mod[(Prime[n + 1] - Prime[n])*PrimePi[n]/n, 8]] == 5, Prime[n], {}], {n, 1, 400}]]
%Y A109559 Cf. A000040, A000720, A001359.
%Y A109559 Cf. A109556-A109569 for m = 2..15.
%K A109559 nonn,less
%O A109559 1,1
%A A109559 _Roger L. Bagula_, Jun 27 2005
%E A109559 Name edited, offset corrected and more terms added by _Amiram Eldar_, Jun 02 2025