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 A083084 #9 Sep 08 2022 08:45:10 %S A083084 1,9,141,2893,73081,2200977,77189509,3095295861,139872233073, %T A083084 7039013063065,390656716635901,23714578436644509,1563646420268423401, %U A083084 111315499088924632353,8511391223995285616373,695805743909499121660357 %N A083084 A diagonal of number array A083075. %H A083084 Vincenzo Librandi, <a href="/A083084/b083084.txt">Table of n, a(n) for n = 0..300</a> %F A083084 a(n) = ((n+3)*(2n+9)^n + 1)/(n+4). %o A083084 (Magma) [((n+3)*(2*n+9)^n+1)/(n+4): n in [0..20]]; // _Vincenzo Librandi_, Nov 12 2011 %Y A083084 Cf. A083083, A083082. %K A083084 easy,nonn %O A083084 0,2 %A A083084 _Paul Barry_, Apr 23 2003