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 A046222 #9 Jul 02 2025 16:01:56 %S A046222 1,1,1,2,3,1,11,1,40,1,147,1,546,1,2046,1,7722,1,29315,1,111826,1, %T A046222 428298,1,1646008,1,6344366,1,24515700,1,94942620,1,368404110,1, %U A046222 1431985635,1,5574725970,1,21732560850,1,84828633120,1,331488081210,1 %N A046222 First numerator and then denominator of central elements of 1/2-Pascal triangle. %e A046222 1/1; 1/1 1/1; 1/1 1/2 1/1; 1/1 3/2 3/2 1/1; 1/1 5/2 3/1 5/2 1/1; 1/1 7/2 11/2 11/2 7/2 1/1; 1/1 9/2 9/1 11/1 9/1 9/2 1/1; 1/1 11/2 27/2 20/1 20/1 27/2 11/2 1/1; ... %Y A046222 Cf. A046213. %K A046222 nonn %O A046222 1,4 %A A046222 _Mohammad K. Azarian_ %E A046222 More terms from _James Sellers_, Dec 13 1999