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 A097515 #10 Jul 02 2024 07:18:42
%S A097515 18,198,2006,19980,199994,1999986,20000010,199999996,1999999944,
%T A097515 19999999986,199999999980,2000000000028,20000000000008,
%U A097515 200000000000004,2000000000000026,19999999999999998,200000000000000000,1999999999999999992,20000000000000000012,200000000000000000028
%N A097515 a(n) = (largest prime < 10^n) + (smallest prime > 10^n).
%F A097515 a(n) = A003618(n) + A003617(n+1). - _Amiram Eldar_, Jul 02 2024
%t A097515 Table[NextPrime[10^n,-1]+NextPrime[10^n],{n,20}] (* _Harvey P. Dale_, May 03 2018 *)
%Y A097515 Cf. A003617, A003618.
%K A097515 nonn
%O A097515 1,1
%A A097515 _Cino Hilliard_, Aug 27 2004
%E A097515 More terms from _Amiram Eldar_, Jul 02 2024