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 A175685 #15 May 12 2019 02:22:48 %S A175685 1,1,1,1,1,1,2,2,1,1,1,3,2,1,1,3,4,3,2,1,1,1,7,5,3,2,1,1,4,7,8,5,3,2, %T A175685 1,1,1,14,12,8,5,3,2,1,1 %N A175685 Array a(n,m) = Sum_{j=floor((n-1)/2)-m..floor(n-1)/2} binomial(n-j-1,j) read by antidiagonals. %C A175685 A102426 defines an array of binomials in which partial sums of row n yield row a(n,.). %D A175685 Burton, David M., Elementary number theory, McGraw Hill, N.Y., 2002, p. 286. %e A175685 a(n,m) starts in row n=1 as %e A175685 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... %e A175685 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, ... %e A175685 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, ... %e A175685 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, ... %e A175685 1, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, ... %e A175685 3, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, ... %e A175685 1, 7, 12, 13, 13, 13, 13, 13, 13, 13, 13, ... %e A175685 4, 14, 20, 21, 21, 21, 21, 21, 21, 21, 21, ... %e A175685 1, 11, 26, 33, 34, 34, 34, 34, 34, 34, 34, ... %p A175685 A175685 := proc(n,m) upl := floor( (n-1)/2) ; add( binomial(n-j-1,j),j=upl-m .. upl) ; end proc: # _R. J. Mathar_, Dec 05 2010 %t A175685 a = Table[Table[Sum[Binomial[n -j - 1, j], {j, Floor[(n - 1)/2] - m, Floor[(n - %t 1)/2]}], {n, 0, 10}], {m, 0, 10}]; %t A175685 Table[Table[a[[m, n - m + 1]], {m, 1, n - 1}], {n, 1, 10}];Flatten[%] %Y A175685 Cf. A000045, A011973, A102426. %K A175685 nonn,tabl,easy %O A175685 1,7 %A A175685 _Roger L. Bagula_, Dec 04 2010