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 A319730 #20 Feb 18 2025 08:11:03 %S A319730 1,0,1,0,3,2,0,6,11,3,0,13,48,33,5,0,24,165,212,75,7,0,48,573,1253, %T A319730 798,172,11,0,86,1759,6114,6175,2284,326,15,0,160,5473,29573,45040, %U A319730 25697,6198,631,22,0,282,16051,131488,289685,238516,86189,14519,1102,30 %N A319730 Number T(n,k) of plane partitions of n into parts of exactly k sorts which are introduced in ascending order; triangle T(n,k), n>=0, 0<=k<=n, read by rows. %H A319730 Alois P. Heinz, <a href="/A319730/b319730.txt">Rows n = 0..50, flattened</a> %H A319730 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/PlanePartition.html">Plane partition</a> %H A319730 Wikipedia, <a href="https://en.wikipedia.org/wiki/Plane_partition">Plane partition</a> %F A319730 T(n,k) = 1/k! * A319600(n,k). %e A319730 Triangle T(n,k) begins: %e A319730 1; %e A319730 0, 1; %e A319730 0, 3, 2; %e A319730 0, 6, 11, 3; %e A319730 0, 13, 48, 33, 5; %e A319730 0, 24, 165, 212, 75, 7; %e A319730 0, 48, 573, 1253, 798, 172, 11; %e A319730 0, 86, 1759, 6114, 6175, 2284, 326, 15; %e A319730 0, 160, 5473, 29573, 45040, 25697, 6198, 631, 22; %e A319730 0, 282, 16051, 131488, 289685, 238516, 86189, 14519, 1102, 30; %e A319730 ... %Y A319730 Columns k=0-1 give: A000007, A000219 (for n>0). %Y A319730 Main diagonal gives A000041. %Y A319730 Row sums give A319731. %Y A319730 T(2n,n) gives A319732. %Y A319730 Cf. A256130, A319600. %K A319730 nonn,tabl %O A319730 0,5 %A A319730 _Alois P. Heinz_, Sep 26 2018