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 A323432 #4 Jan 17 2019 09:57:38
%S A323432 1,1,2,4,6,9,15,20,30,42,59,79,112,146,199,264,350,455,603,774,1010,
%T A323432 1297,1668,2124,2724,3441,4372,5513,6955,8718,10960,13670,17091,21264,
%U A323432 26454,32786,40667,50215,62048,76435,94126
%N A323432 Number of semistandard rectangular plane partitions of n.
%C A323432 Number of ways to fill a (not necessarily square) matrix with the parts of an integer partition of n so that the rows are weakly decreasing and the columns are strictly decreasing.
%e A323432 The a(6) = 15 matrices:
%e A323432 [6] [51] [42] [411] [33] [321] [3111] [222] [2211] [21111] [111111]
%e A323432 .
%e A323432 [5] [4] [22]
%e A323432 [1] [2] [11]
%e A323432 .
%e A323432 [3]
%e A323432 [2]
%e A323432 [1]
%t A323432 Table[Sum[Length[Select[Union[Tuples[IntegerPartitions[#,{k}]&/@ptn]],And@@(OrderedQ[#,Greater]&/@Transpose[#])&]],{ptn,IntegerPartitions[n]},{k,Min[ptn]}],{n,30}]
%Y A323432 Cf. A000219, A003293, A047966, A089299, A101509, A114736, A117433, A299968, A319066.
%Y A323432 Cf. A323301, A323307, A323429, A323430, A323431, A323435, A323436, A323438.
%K A323432 nonn
%O A323432 0,3
%A A323432 _Gus Wiseman_, Jan 16 2019