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 A323971 #6 Feb 09 2019 21:12:32
%S A323971 1,15,155,1332,8342,41586,174844,642815,2117690,6362806,17671203,
%T A323971 45844681,112047610,259796057,574776968,1219349012,2490738686,
%U A323971 4916477305,9406990883,17494038498,31695618318,56063910644,96993880940,164397619093,273384891666,446635565576
%N A323971 Number of 7 X n integer matrices (m_{i,j}) such that m_{1,1}=0, m_{7,n}=2, and all rows, columns, and falling diagonals are (weakly) monotonic without jumps of 2.
%H A323971 Alois P. Heinz, <a href="/A323971/b323971.txt">Table of n, a(n) for n = 0..10000</a>
%F A323971 G.f.: -(5*x^15 -69*x^14 +443*x^13 -1750*x^12 +4744*x^11 -9317*x^10 +13630*x^9 -15026*x^8 +12430*x^7-7561*x^6 +3263*x^5-823*x^4 +127*x^3 +35*x^2+1) / (x-1)^15.
%Y A323971 Row (or column) 7 of array in A323846.
%K A323971 nonn,easy
%O A323971 0,2
%A A323971 _Alois P. Heinz_, Feb 09 2019