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 A094338 #8 Mar 01 2019 16:23:36
%S A094338 0,-5,5,20,17,39,129,140,127,305,431,448,603,777,1037,1540,1313,1951,
%T A094338 2373,2450,2861,3407,3975,4656,5329,6073,6951,7092,7983,8091,11063,
%U A094338 11290,14695,12749,14143,14276,18495,20201,20571,25612,21065,28283
%N A094338 (Sum of composites among next n numbers)-(sum of primes among next n numbers).
%H A094338 Harvey P. Dale, <a href="/A094338/b094338.txt">Table of n, a(n) for n = 1..1000</a>
%e A094338 a(4) = (8+9+10)-(7) =20.
%t A094338 scsp[n_]:=Module[{prs=Select[n,PrimeQ]},Total[Complement[n,prs]]-Total[ prs]]; With[{nn=50},scsp/@TakeList[Range[(nn(nn+1))/2],Range[nn]]]/. (1->0) (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Mar 01 2019 *)
%Y A094338 Cf. A094337.
%K A094338 sign
%O A094338 1,2
%A A094338 _Amarnath Murthy_, May 17 2004
%E A094338 More terms from _Sean A. Irvine_, Oct 13 2009