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 A191621 #21 Apr 26 2021 14:54:03
%S A191621 2,5,29,273,3377,51013,908609,18640961,432891137,11225320101,
%T A191621 321504185345,10079828372881,343360783937537,12627774819845669,
%U A191621 498676704524517377,21046391759976988929,945381827279671853057,45032132922921758270917
%N A191621 a(n) = ((n+1)^n-(n-1)^n)/2+1.
%C A191621 The next prime in the sequence, after 2, 5 and 29, has at least 888 digits (n >= 349).
%e A191621 a(1)=2 because ((1+1)^1-(1-1)^1)/2+1=2,
%e A191621 a(2)=5 because ((2+1)^2-(2-1)^2)/2+1=5,
%e A191621 a(3)=29 because ((3+1)^3-(3-1)^3)/2+1=29.
%t A191621 Table[((n+1)^n-(n-1)^n)/2+1,{n,20}] (* _Harvey P. Dale_, Oct 27 2019 *)
%K A191621 nonn
%O A191621 1,1
%A A191621 _Juri-Stepan Gerasimov_, Jun 14 2011