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 A029638 #18 Feb 16 2025 08:32:35 %S A029638 2,2,3,2,4,5,2,5,9,7,2,6,14,16,9,2,7,20,30,25,11,2,8,27,50,55,36,13,2, %T A029638 9,35,77,105,91,49,15,2,10,44,112,182,196,140,64,17,2,11,54,156,294, %U A029638 378,336,204,81,19,2,12,65,210,450,672,714,540,285,100,21,2,13,77,275,660,1122 %N A029638 Numbers in the (1,2)-Pascal triangle A029635 that are different from 1. %D A029638 D. M. Bressoud, Proofs and Confirmations, Camb. Univ. Press, 1999; triangle on page 6, denominators. %H A029638 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/AlternatingSignMatrix.html">Alternating Sign Matrix.</a> %H A029638 D. Zeilberger, <a href="http://www.math.rutgers.edu/~zeilberg/DaveRobbins/guess.html">Dave Robbins's Art of Guessing</a>, Adv. in Appl. Math. 34 (2005), 939-954. %e A029638 Triangle begins: %e A029638 2; %e A029638 3, 2; %e A029638 4, 5, 2; %e A029638 5, 9, 7, 2; %e A029638 6, 14, 16, 9, 2; %e A029638 7, 20, 30, 25, 11, 2; %e A029638 ... %Y A029638 Cf. A048601, A029656. %K A029638 nonn,tabl,frac %O A029638 1,1 %A A029638 _Mohammad K. Azarian_ %E A029638 More terms from _David W. Wilson_ %E A029638 Leading 2 inserted as consequence of change in A029635 by _Sean A. Irvine_, Mar 01 2020