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 A275991 #20 Sep 02 2025 18:39:42
%S A275991 5,10,14,16,18,24,26,28,30,32,40,36,38,46,50,48,44,46,46,60,64,60,66,
%T A275991 62,66,66,70,74,84,84,72,92,90,90,84,88,94,94,96,96,92,100,102,114,
%U A275991 114,114,106,114,120,120,126,134,138,132,132,134,140,148,144,152,156,150
%N A275991 a(n) = prime(composite(n)) - prime(n).
%H A275991 Harvey P. Dale, <a href="/A275991/b275991.txt">Table of n, a(n) for n = 1..1000</a>
%F A275991 a(n) = A000040(A002808(n)) - A000040(n) = A088982(n) - A000040(n).
%e A275991 For n=3, prime(composite(3)) = 19, and prime(3) = 5, therefore a(3) = 19 - 5 = 14.
%t A275991 Module[{nn=100,cmps},cmps=Select[Range[nn],CompositeQ];Prime[cmps]-Prime[Range[Length[cmps]]]] (* _Harvey P. Dale_, Sep 02 2025 *)
%Y A275991 Cf. A088982.
%K A275991 nonn,changed
%O A275991 1,1
%A A275991 _Terry D. Grant_, Aug 15 2016
%E A275991 Previous Mathematica program replaced by _Harvey P. Dale_, Sep 02 2025