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 A273967 #4 Jun 05 2016 14:37:59 %S A273967 15,1264,24587,49534,36817,40569,36570,90627,89429,182457,100921, %T A273967 179282,121279,301658,206783,445549,325633,652935,526099,1011751, %U A273967 897383,1627068,1524277,2600188,2533039,4097718,4108747,6343186,6487741,9626296,9987409 %N A273967 Number of nX4 0..3 arrays with no three equal values forming an isosceles triangle, and new values introduced in 0..3 order. %C A273967 Column 4 of A273968. %H A273967 R. H. Hardin, <a href="/A273967/b273967.txt">Table of n, a(n) for n = 1..60</a> %e A273967 Some solutions for n=4 %e A273967 ..0..1..1..2. .0..0..1..2. .0..1..1..2. .0..0..1..2. .0..0..1..1 %e A273967 ..3..3..2..3. .1..1..0..0. .0..3..3..2. .3..2..1..2. .2..3..3..3 %e A273967 ..0..1..2..0. .3..3..3..2. .3..1..1..2. .2..3..1..3. .1..1..0..0 %e A273967 ..3..1..2..0. .0..2..2..1. .2..0..0..0. .0..0..1..3. .3..0..1..2 %Y A273967 Cf. A273968. %K A273967 nonn %O A273967 1,1 %A A273967 _R. H. Hardin_, Jun 05 2016