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 A011857 #10 Jul 08 2025 02:40:47
%S A011857 2,3,1,4,3,1,5,5,3,1,6,7,6,3,1,7,10,11,8,4,1,8,14,18,17,11,4,1,9,18,
%T A011857 28,31,25,14,5,1,10,22,40,52,50,35,17,5,1,11,27,55,82,92,77,47,20,6,1,
%U A011857 12,33,73,123,158,154,113,61,24,6,1,13,39,95,178,257,286,245,160
%N A011857 Triangle of numbers [ C(n,k)/k ], k=1..n-1.
%t A011857 Flatten[Table[Floor[Binomial[n,k]/k],{n,20},{k,n-1}]] (* _Harvey P. Dale_, Apr 19 2015 *)
%Y A011857 Columns include A011848, A011849, A011850, A011851, A011852, A011853, A011854, A011855, A011856. Row sums are in A101687. Cf. A011847.
%K A011857 tabl,nonn,easy
%O A011857 2,1
%A A011857 _N. J. A. Sloane_