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 A269950 #11 Mar 08 2020 06:54:56 %S A269950 1,3,1,15,5,1,35,35,7,1,315,105,63,9,1,693,1155,231,99,11,1,3003,3003, %T A269950 3003,429,143,13,1,6435,15015,9009,6435,715,195,15,1,109395,36465, %U A269950 51051,21879,12155,1105,255,17,1,230945,692835,138567,138567,46189,20995,1615,323,19,1 %N A269950 Triangle read by rows, T(n,k) = denominator(binomial(1/2,n-k))*binomial(n+1/2, k+1/2), for n>=0 and 0<=k<=n. %e A269950 Triangle starts: %e A269950 [1] %e A269950 [3, 1] %e A269950 [15, 5, 1] %e A269950 [35, 35, 7, 1] %e A269950 [315, 105, 63, 9, 1] %e A269950 [693, 1155, 231, 99, 11, 1] %e A269950 [3003, 3003, 3003, 429, 143, 13, 1] %e A269950 [6435, 15015, 9009, 6435, 715, 195, 15, 1] %o A269950 (Sage) %o A269950 A269950 = lambda n,k: binomial(1/2,n-k).denom()*binomial(n+1/2,k+1/2) %o A269950 for n in range(8): print([A269950(n,k) for k in (0..n)]) %Y A269950 Cf. A001803 (col. 0), A161199 (col. 1), A161201 (col. 2). %Y A269950 Cf. A269949. %K A269950 nonn,tabl %O A269950 0,2 %A A269950 _Peter Luschny_, Apr 07 2016