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 A238960 #19 Apr 25 2020 18:14:05 %S A238960 0,0,1,2,1,3,6,2,5,6,10,16,2,6,8,14,16,26,40,3,8,11,12,18,23,27,36,42, %T A238960 64,96,3,9,13,15,22,29,32,37,46,58,67,88,102,152,224,4,11,16,19,20,26, %U A238960 36,41,48,52,56,74,80,93,108,112,140,162,208,240,352,512 %N A238960 The number of arcs from odd to even level vertices in divisor lattice in graded colexicographic order. %H A238960 Andrew Howroyd, <a href="/A238960/b238960.txt">Table of n, a(n) for n = 0..2713</a> (rows 0..20) %H A238960 S.-H. Cha, E. G. DuCasse, and L. V. Quintas, <a href="http://arxiv.org/abs/1405.5283">Graph Invariants Based on the Divides Relation and Ordered by Prime Signatures</a>, arXiv:1405.5283 [math.NT], 2014, Table A.1 entry |E_O(S)|. %F A238960 T(n,k) = A238951(A036035(n,k)). %F A238960 From _Andrew Howroyd_, Apr 25 2020: (Start) %F A238960 T(n,k) = floor(A238953(n,k)/2). %F A238960 T(n,k) = A238953(n,k) - A238959(n,k). (End) %e A238960 Triangle T(n,k) begins: %e A238960 0; %e A238960 0; %e A238960 1, 2; %e A238960 1, 3, 6; %e A238960 2, 5, 6, 10, 16; %e A238960 2, 6, 8, 14, 16, 26, 40; %e A238960 3, 8, 11, 12, 18, 23, 27, 36, 42, 64, 96; %e A238960 ... %Y A238960 Cf. A238951 in graded colexicographic order. %Y A238960 Cf. A036035, A238953, A238959, A238973. %K A238960 nonn,tabf %O A238960 0,4 %A A238960 _Sung-Hyuk Cha_, Mar 07 2014 %E A238960 Offset changed and terms a(50) and beyond from _Andrew Howroyd_, Apr 25 2020