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 A128442 #2 Mar 30 2012 18:57:10 %S A128442 1,2,2,4,4,2,5,6,5,4,7,8,8,8,5,8,10,11,12,11,8,9,12,14,16,16,16,11,11, %T A128442 14,16,20,22,24,22,16,12,16,19,24,28,32,33,32,22,14,18,22,28,33,40,45, %U A128442 48,45,32,15,20,25,32,39,48,56,64,67,64,45,16,22,28,36,45,56,67,80,90 %N A128442 Array T by antidiagonals: T(n,k)=Floor(k*2^(n/2)). %C A128442 Row 1 = A001951; Row 2 = A005843; Row 3 = A022842; Row 4 = A008586; Column 1 = A017910; T(n,n) = A128441(n). %e A128442 Northwest corner: %e A128442 1 2 4 5 7 %e A128442 2 4 6 8 10 %e A128442 2 5 8 11 14 %e A128442 4 8 12 16 20 %e A128442 5 11 16 22 28 %Y A128442 Cf. A005843, A008586, A128441. %K A128442 nonn,tabl %O A128442 1,2 %A A128442 _Clark Kimberling_, Mar 03 2007