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 A224011 #6 Jul 23 2025 04:51:08 %S A224011 36,1296,31324,595822,9866389,150787422,2200064042,31256208954, %T A224011 437370837827,6067995150599,83782568814192,1153696422958020, %U A224011 15862451436172435,217909148559859942,2992039535598090819 %N A224011 Number of nX7 0..2 arrays with rows nondecreasing and antidiagonals unimodal. %C A224011 Column 7 of A224012 %H A224011 R. H. Hardin, <a href="/A224011/b224011.txt">Table of n, a(n) for n = 1..210</a> %F A224011 Empirical: a(n) = 36*a(n-1) -505*a(n-2) +3667*a(n-3) -15271*a(n-4) +38113*a(n-5) -59621*a(n-6) +53813*a(n-7) -125335*a(n-8) +657330*a(n-9) -1326014*a(n-10) +2644047*a(n-11) +3529521*a(n-12) +7803900*a(n-13) +959690*a(n-14) +28175350*a(n-15) +27269532*a(n-16) +18725976*a(n-17) +1826832*a(n-18) +1263744*a(n-19) %e A224011 Some solutions for n=3 %e A224011 ..0..0..0..0..1..1..1....0..0..0..0..2..2..2....0..0..0..0..1..2..2 %e A224011 ..0..0..0..0..2..2..2....0..0..0..1..2..2..2....1..1..1..1..1..1..1 %e A224011 ..0..0..0..0..0..1..1....0..1..1..1..1..1..1....0..0..0..0..1..1..1 %K A224011 nonn %O A224011 1,1 %A A224011 _R. H. Hardin_ Mar 30 2013