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 A267997 #12 Mar 21 2025 21:57:11 %S A267997 4,16,16,64,256,64,250,4096,4096,250,964,62500,262144,62500,964,3674, %T A267997 929296,15625000,15625000,929296,3674,13868,13498276,895841344, %U A267997 3552627426,895841344,13498276,13868,51917,192321424,49592666024,766970396055,766970396055,49592666024,192321424,51917 %N A267997 T(n,k) = number of n X k 0..3 arrays with every repeated value in every row and column greater than or equal to the previous repeated value. %H A267997 R. H. Hardin, <a href="/A267997/b267997.txt">Table of n, a(n) for n = 1..60</a> %F A267997 Empirical for column k: %F A267997 k=1: [linear recurrence of order 8] %F A267997 k=2: [order 21] %F A267997 k=3: [order 40] %e A267997 Table starts: %e A267997 4 16 64 250 964 %e A267997 16 256 4096 62500 929296 %e A267997 64 4096 262144 15625000 895841344 %e A267997 250 62500 15625000 3552627426 766970396055 %e A267997 964 929296 895841344 766970396055 615504325372174 %e A267997 3674 13498276 49592666024 158016399692284 465926430628469626 %e A267997 13868 192321424 2667113508032 31323853192497584 ... %e A267997 51917 2695374889 139935778112213 ... %e A267997 192980 37241280400 ... %e A267997 712868 ... %e A267997 ... %e A267997 Some solutions for n=2 k=4: %e A267997 ..3..1..2..0....0..1..3..3....1..2..1..1....3..2..3..1....2..2..0..1 %e A267997 ..3..0..3..0....1..0..2..0....0..3..3..3....3..2..0..3....2..1..0..2 %Y A267997 Columns 1..5 are A267975, A267976, A267994, A267995, A267996. %K A267997 nonn,tabl %O A267997 1,1 %A A267997 _R. H. Hardin_, Jan 24 2016 %E A267997 Name corrected by _Andrew Howroyd_, Mar 21 2025