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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.

A361521 Array read by descending antidiagonals. A(n, k) is the number of the nonempty multiset combinations of {0, 1} as defined in A361682.

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%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