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 A083072 #5 Mar 04 2018 21:17:27 %S A083072 1,4,29,286,3511,51668,888889,17538454,390892451,9720791092, %T A083072 267004296901,8031916155134,262709978263279,9285541905849316, %U A083072 352765522430193905,14337731083770642838,620867368421052631579 %N A083072 A subdiagonal of number array A083064. %F A083072 a(n) = ((n+2)*(n+4)^n + 1)/(n+3). %Y A083072 Cf. A083071, A083069. %K A083072 easy,nonn %O A083072 0,2 %A A083072 _Paul Barry_, Apr 21 2003