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 A323972 #5 Feb 09 2019 21:01:55 %S A323972 1,21,259,2570,18546,106067,508484,2117690,7852836,26400811,81594028, %T A323972 234380304,631352789,1606571023,3885713191,8979237218,19912769178, %U A323972 42540796862,87841523926,175820917355,341996038445,647926774508,1197980968295,2165529201795,3833173915877 %N A323972 Number of 8 X n integer matrices (m_{i,j}) such that m_{1,1}=0, m_{8,n}=2, and all rows, columns, and falling diagonals are (weakly) monotonic without jumps of 2. %H A323972 Alois P. Heinz, <a href="/A323972/b323972.txt">Table of n, a(n) for n = 0..10000</a> %F A323972 G.f.: -(6*x^17 -95*x^16 +707*x^15 -3278*x^14 +10588*x^13 -25239*x^12 +45878*x^11 -64775*x^10 +71619*x^9 -62024*x^8 +41650*x^7 -21151*x^6 +7977*x^5 -1820*x^4 +343*x^3 +38*x^2 +4*x+1) / (x-1)^17. %Y A323972 Row (or column) 8 of array in A323846. %K A323972 nonn,easy %O A323972 0,2 %A A323972 _Alois P. Heinz_, Feb 09 2019