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A321609 Array read by antidiagonals: T(n,k) is the number of inequivalent binary n X n matrices with k ones, under row and column permutations. 5

%I #13 Sep 10 2019 09:11:52

%S 1,0,1,0,1,1,0,0,1,1,0,0,3,1,1,0,0,1,3,1,1,0,0,1,6,3,1,1,0,0,0,7,6,3,

%T 1,1,0,0,0,7,16,6,3,1,1,0,0,0,6,21,16,6,3,1,1,0,0,0,3,39,34,16,6,3,1,

%U 1,0,0,0,1,44,69,34,16,6,3,1,1,0,0,0,1,55,130,90,34,16,6,3,1,1

%N Array read by antidiagonals: T(n,k) is the number of inequivalent binary n X n matrices with k ones, under row and column permutations.

%F T(n,k) = T(k,k) for n > k.

%F T(n,k) = 0 for k > n^2.

%e Array begins:

%e ==========================================================

%e n\k| 0 1 2 3 4 5 6 7 8 9 10 11 12

%e ---+------------------------------------------------------

%e 0 | 1 0 0 0 0 0 0 0 0 0 0 0 0 ...

%e 1 | 1 1 0 0 0 0 0 0 0 0 0 0 0 ...

%e 2 | 1 1 3 1 1 0 0 0 0 0 0 0 0 ...

%e 3 | 1 1 3 6 7 7 6 3 1 1 0 0 0 ...

%e 4 | 1 1 3 6 16 21 39 44 55 44 39 21 16 ...

%e 5 | 1 1 3 6 16 34 69 130 234 367 527 669 755 ...

%e 6 | 1 1 3 6 16 34 90 182 425 870 1799 3323 5973 ...

%e 7 | 1 1 3 6 16 34 90 211 515 1229 2960 6893 15753 ...

%e 8 | 1 1 3 6 16 34 90 211 558 1371 3601 9209 24110 ...

%e 9 | 1 1 3 6 16 34 90 211 558 1430 3825 10278 28427 ...

%e ...

%t permcount[v_List] := Module[{m = 1, s = 0, k = 0, t}, For[i = 1, i <= Length[v], i++, t = v[[i]]; k = If[i > 1 && t == v[[i - 1]], k + 1, 1]; m *= t*k; s += t]; s!/m];

%t c[p_List, q_List, k_] := SeriesCoefficient[Product[Product[(1 + O[x]^(k + 1) + x^LCM[p[[i]], q[[j]]])^GCD[p[[i]], q[[j]]], {j, 1, Length[q]}], {i, 1, Length[p]}], {x, 0, k}];

%t M[m_, n_, k_] := Module[{s = 0}, Do[Do[s += permcount[p]*permcount[q]*c[p, q, k], {q, IntegerPartitions[n]}], {p, IntegerPartitions[m]}]; s/(m!*n!)]

%t Table[M[n - k, n - k, k], {n, 0, 12}, {k, n, 0, -1}] // Flatten (* _Jean-François Alcover_, Sep 10 2019, after _Andrew Howroyd_ *)

%o (PARI)

%o permcount(v) = {my(m=1, s=0, k=0, t); for(i=1, #v, t=v[i]; k=if(i>1&&t==v[i-1], k+1, 1); m*=t*k; s+=t); s!/m}

%o c(p, q, k)={polcoef(prod(i=1, #p, prod(j=1, #q, (1 + x^lcm(p[i], q[j]) + O(x*x^k))^gcd(p[i], q[j]))), k)}

%o M(m, n, k)={my(s=0); forpart(p=m, forpart(q=n, s+=permcount(p) * permcount(q) * c(p, q, k))); s/(m!*n!)}

%o for(n=0, 10, for(k=0, 12, print1(M(n, n, k), ", ")); print); \\ _Andrew Howroyd_, Nov 14 2018

%Y Rows n=6..8 are A052370, A053304, A053305.

%Y Main diagonal is A049311.

%Y Row sums are A002724.

%Y Cf. A052371 (as triangle), A057150, A246106, A318795.

%K nonn,tabl

%O 0,13

%A _Andrew Howroyd_, Nov 14 2018

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