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 A274064 #5 Jun 09 2016 07:53:39 %S A274064 5,50,264,435,546,1209,3272,8412,20634,52751,137707,362923,962095, %T A274064 2559621,6811807,18145756,48384429,129108567,344635575,920181094, %U A274064 2457266397,6562691188,17528571958,46820546020,125067069103,334088127067 %N A274064 Number of nX3 0..2 arrays with no three equal values forming an isosceles right triangle, and new values introduced in 0..2 order. %C A274064 Column 3 of A274065. %H A274064 R. H. Hardin, <a href="/A274064/b274064.txt">Table of n, a(n) for n = 1..210</a> %F A274064 Empirical: a(n) = 7*a(n-1) -19*a(n-2) +26*a(n-3) -9*a(n-4) -55*a(n-5) +156*a(n-6) -233*a(n-7) +196*a(n-8) +46*a(n-9) -418*a(n-10) +768*a(n-11) -848*a(n-12) +431*a(n-13) +281*a(n-14) -1061*a(n-15) +1365*a(n-16) -1061*a(n-17) +405*a(n-18) +443*a(n-19) -737*a(n-20) +805*a(n-21) -537*a(n-22) +119*a(n-23) -34*a(n-24) -224*a(n-25) +132*a(n-26) -105*a(n-27) +130*a(n-28) +8*a(n-29) +83*a(n-30) +2*a(n-31) -31*a(n-32) +9*a(n-33) -57*a(n-34) +5*a(n-35) +7*a(n-36) -2*a(n-37) +10*a(n-38) -2*a(n-40) for n>49 %e A274064 Some solutions for n=4 %e A274064 ..0..1..1. .0..1..2. .0..1..2. .0..1..1. .0..0..1. .0..1..2. .0..1..2 %e A274064 ..2..2..0. .0..1..2. .1..0..2. .0..2..2. .2..1..0. .1..2..0. .0..1..2 %e A274064 ..0..1..2. .0..1..2. .1..2..1. .2..1..0. .2..1..0. .0..0..1. .2..0..0 %e A274064 ..0..1..2. .2..0..0. .2..0..0. .0..0..2. .2..1..0. .2..2..1. .1..2..1 %Y A274064 Cf. A274065. %K A274064 nonn %O A274064 1,1 %A A274064 _R. H. Hardin_, Jun 09 2016