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 A049653 #10 Sep 08 2022 08:44:58
%S A049653 1,1,1,3,1,1,3,1,1,3,1,3,5,1,1,3,5,1,3,1,1,3,1,3,5,1,3,5,1,1,3,5,1,3,
%T A049653 1,1,3,5,1,3,1,3,5,1,3,5,7,1,3,1,1,3,1,1,3,1,3,5,7,9,11,13,1,3,1,3,5,
%U A049653 1,1,3,5,7,9,1,1,3,5,1,3,5,1,3,1,3,5,1,3,5,1,1,3,5,7
%N A049653 a(n) = 2*n - prevprime(2*n).
%H A049653 G. C. Greubel, <a href="/A049653/b049653.txt">Table of n, a(n) for n = 2..5000</a>
%F A049653 a(n) = A049711(2*n). - _R. J. Mathar_, Oct 26 2015
%t A049653 Table[2*n - NextPrime[2*n, -1], {n, 2, 50}] (* _G. C. Greubel_, Dec 05 2017 *)
%o A049653 (Magma) [2*n - NthPrime(#PrimesUpTo(2*n)): n in [2..50]]; // _G. C. Greubel_, Dec 05 2017
%o A049653 (PARI) for(n=2,50, print1(2*n - precprime(2*n), ", ")) \\ _G. C. Greubel_, Dec 05 2017
%Y A049653 Cf. A049613, A049711, A049716, A049847.
%K A049653 nonn
%O A049653 2,4
%A A049653 _N. J. A. Sloane_