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 A083083 #10 Sep 08 2022 08:45:10
%S A083083 1,7,97,1831,43393,1242375,41818561,1620979687,71191804801,
%T A083083 3496805826823,190053352702753,11329044782441127,735151931535979777,
%U A083083 51600331868857972231,3896042468112362132353,314921475287825567805799
%N A083083 A diagonal of number array A083075.
%H A083083 Vincenzo Librandi, <a href="/A083083/b083083.txt">Table of n, a(n) for n = 0..300</a>
%F A083083 a(n) = ((n+2)*(2n+7)^n + 1)/(n+3).
%t A083083 Table[((n+2)(2n+7)^n+1)/(n+3),{n,0,20}] (* _Harvey P. Dale_, Nov 18 2021 *)
%o A083083 (Magma) [((n+2)*(2*n+7)^n+1)/(n+3): n in [0..20]]; // _Vincenzo Librandi_, Nov 12 2011
%Y A083083 Cf. A083082, A083084.
%K A083083 easy,nonn
%O A083083 0,2
%A A083083 _Paul Barry_, Apr 23 2003