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 A162991 #8 Mar 31 2024 19:15:44 %S A162991 4,9,64,900,20736,705600,33177600,2057529600,162570240000, %T A162991 15933509222400,1896219279360000,269276305858560000, %U A162991 44970736429301760000,8724552309817344000000,1945613940877311344640000 %N A162991 The first right hand column of triangle A162990. %F A162991 a(n) = ((n+1)!/n)^2 for n = 1, 2, 3, ... . %t A162991 Array[((#+1)!/#)^2 &, 20] (* _Paolo Xausa_, Mar 31 2024 *) %Y A162991 A001048(n) equals the square root of a(n). %Y A162991 A162992 is the second right hand column of triangle A162990. %K A162991 easy,nonn %O A162991 1,1 %A A162991 _Johannes W. Meijer_, Jul 21 2009