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 A361521 #7 Mar 23 2023 07:57:51 %S A361521 0,0,0,0,2,0,0,5,4,0,0,9,12,6,0,0,14,24,21,8,0,0,20,40,45,32,10,0,0, %T A361521 27,60,78,72,45,12,0,0,35,84,120,128,105,60,14,0,0,44,112,171,200,190, %U A361521 144,77,16,0,0,54,144,231,288,300,264,189,96,18,0 %N A361521 Array read by descending antidiagonals. A(n, k) is the number of the nonempty multiset combinations of {0, 1} as defined in A361682. %C A361521 A detailed combinatorial interpretation can be found in A361682. %F A361521 A(n, k) = n*k*(4 + n*(k - 1))/2. %F A361521 T(n, k) = k*(n - k)*(4 + k*(n - k - 1))/2. %F A361521 A(n, k) = A361682(n, k) - 1. %e A361521 [0] 0, 0, 0, 0, 0, 0, 0, 0, ... A000004 %e A361521 [1] 0, 2, 5, 9, 14, 20, 27, 35, ... A000096 %e A361521 [2] 0, 4, 12, 24, 40, 60, 84, 112, ... A046092 %e A361521 [3] 0, 6, 21, 45, 78, 120, 171, 231, ... A081266 %e A361521 [4] 0, 8, 32, 72, 128, 200, 288, 392, ... A139098 %e A361521 [5] 0, 10, 45, 105, 190, 300, 435, 595, ... %e A361521 [6] 0, 12, 60, 144, 264, 420, 612, 840, ... A153792 %e A361521 [7] 0, 14, 77, 189, 350, 560, 819, 1127, ... %e A361521 | A028347 | A163761 %e A361521 A005843 A067725 %e A361521 . %e A361521 [0] 0; %e A361521 [1] 0, 0; %e A361521 [2] 0, 2, 0; %e A361521 [3] 0, 5, 4, 0; %e A361521 [4] 0, 9, 12, 6, 0; %e A361521 [5] 0, 14, 24, 21, 8, 0; %e A361521 [6] 0, 20, 40, 45, 32, 10, 0; %e A361521 [7] 0, 27, 60, 78, 72, 45, 12, 0; %e A361521 [8] 0, 35, 84, 120, 128, 105, 60, 14, 0; %e A361521 [9] 0, 44, 112, 171, 200, 190, 144, 77, 16, 0; %p A361521 A := (n, k) -> n*k*(4 + n*(k - 1))/2: %p A361521 for n from 0 to 7 do seq(A(n, k), k = 0..7) od; %Y A361521 Rows: A000004, A000096, A046092, A081266, A139098, A153792. %Y A361521 Columns: A000004, A005843, A028347, A067725, A163761, A068380. %Y A361521 Cf. A361682. %K A361521 nonn,tabl %O A361521 0,5 %A A361521 _Peter Luschny_, Mar 22 2023