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 A223811 #6 Jul 23 2025 04:33:14 %S A223811 4,16,16,50,256,50,130,2500,2500,130,296,16900,58806,16900,296,610, %T A223811 87616,825896,825896,87616,610,1163,372100,8165133,20847008,8165133, %U A223811 372100,1163,2083,1352569,62305953,342521725,342521725,62305953,1352569,2083 %N A223811 T(n,k)=Number of nXk 0..3 arrays with rows, columns, diagonals and antidiagonals unimodal. %C A223811 Table starts %C A223811 ....4.......16..........50............130.............296.............610 %C A223811 ...16......256........2500..........16900...........87616..........372100 %C A223811 ...50.....2500.......58806.........825896.........8165133........62305953 %C A223811 ..130....16900......825896.......20847008.......342521725......4146732319 %C A223811 ..296....87616.....8165133......342521725......8597979566....151474085262 %C A223811 ..610...372100....62305953.....4146732319....151474085262...3678996027680 %C A223811 .1163..1352569...388531932....39816673636...2058985931297..66795003874023 %C A223811 .2083..4338889..2057610878...317796753758..22901512677629.975436194200049 %C A223811 .3544.12559936..9513089522..2176384736806.216485354275124 %C A223811 .5776.33362176.39201336756.13081738670880 %H A223811 R. H. Hardin, <a href="/A223811/b223811.txt">Table of n, a(n) for n = 1..97</a> %F A223811 Empirical: columns k=1..5 are polynomials of degree 6*k for n>0,0,0,8,15 %e A223811 Some solutions for n=3 k=4 %e A223811 ..0..0..3..0....1..1..1..1....0..1..0..0....0..0..2..1....0..0..3..1 %e A223811 ..0..0..2..2....0..2..3..1....1..2..3..2....1..3..2..1....0..1..3..1 %e A223811 ..0..2..2..0....0..2..2..1....1..2..2..3....0..2..3..3....1..3..0..0 %Y A223811 Column 1 is A223659 %Y A223811 Column 2 is A223756 %K A223811 nonn,tabl %O A223811 1,1 %A A223811 _R. H. Hardin_ Mar 27 2013