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 A046577 #9 Jul 02 2025 16:01:57 %S A046577 4,5,4,9,4,19,4,13,8,4,17,2,35,4,49,4,21,4,119,2,35,4,25,4,259,4,189, %T A046577 4,95,4,29,112,71,31,4,33,2,483,183,102,4,157,4,37,2,849,285,4,565,2, %U A046577 97,4,41,2,1815,2,1419,4,1705,4,759,4,235,4,45,1617,4,4543,616,2,497,70,4 %N A046577 First denominator and then numerator of the elements to the right of the central elements of the 1/4-Pascal triangle (by row), excluding 1's. %e A046577 1/1; 1/1 1/1; 1/1 1/4 1/1; 1/1 5/4 5/4 1/1; 1/1 9/4 5/2 9/4 1/1; 1/1 13/4 19/4 19/4 13/4 1/1; 1/1 17/4 8/1 19/2 8/1 17/4 1/1; 1/1 21/4 49/4 35/2 35/2 49/4 21/4 1/1; ... %Y A046577 Cf. A046563. %K A046577 nonn %O A046577 1,1 %A A046577 _Mohammad K. Azarian_ %E A046577 More terms from _James Sellers_, Dec 14 1999