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 A324362 #24 May 03 2021 10:10:42 %S A324362 0,0,1,0,1,1,0,1,3,4,0,1,5,13,15,0,1,7,28,67,76,0,1,9,49,179,411,455, %T A324362 0,1,11,76,375,1306,2921,3186,0,1,13,109,679,3181,10757,23633,25487,0, %U A324362 1,15,148,1115,6576,29843,98932,214551,229384,0,1,17,193,1707,12151,69299,307833,1006007,2160343,2293839 %N A324362 Total number of occurrences of k in the (signed) displacement sets of all permutations of [n+k] divided by k!; square array A(n,k), n>=0, k>=0, read by antidiagonals. %H A324362 Alois P. Heinz, <a href="/A324362/b324362.txt">Antidiagonals n = 0..140, flattened</a> %H A324362 Wikipedia, <a href="https://en.wikipedia.org/wiki/Permutation">Permutation</a> %F A324362 E.g.f. of column k: (1-exp(-x))/(1-x)^(k+1). %F A324362 A(n,k) = -1/k! * Sum_{j=1..n} (-1)^j * binomial(n,j) * (n+k-j)!. %F A324362 A(n,k) = A306234(n+k,k). %e A324362 Square array A(n,k) begins: %e A324362 0, 0, 0, 0, 0, 0, 0, ... %e A324362 1, 1, 1, 1, 1, 1, 1, ... %e A324362 1, 3, 5, 7, 9, 11, 13, ... %e A324362 4, 13, 28, 49, 76, 109, 148, ... %e A324362 15, 67, 179, 375, 679, 1115, 1707, ... %e A324362 76, 411, 1306, 3181, 6576, 12151, 20686, ... %e A324362 455, 2921, 10757, 29843, 69299, 142205, 266321, ... %p A324362 A:= (n, k)-> -add((-1)^j*binomial(n, j)*(n+k-j)!, j=1..n)/k!: %p A324362 seq(seq(A(n, d-n), n=0..d), d=0..12); %t A324362 m = 10; %t A324362 col[k_] := col[k] = CoefficientList[(1-Exp[-x])/(1-x)^(k+1)+O[x]^(m+1), x]* Range[0, m]!; %t A324362 A[n_, k_] := col[k][[n+1]]; %t A324362 Table[A[n, d-n], {d, 0, m}, {n, 0, d}] // Flatten (* _Jean-François Alcover_, May 03 2021 *) %Y A324362 Columns k=0-10 give: A002467, A180191(n+1), A324352, A324353, A324354, A324355, A324356, A324357, A324358, A324359, A324360. %Y A324362 Rows n=0-3 give: A000004, A000012, A005408, A056107(k+1). %Y A324362 Main diagonal gives A324361. %Y A324362 Cf. A306234. %K A324362 nonn,tabl %O A324362 0,9 %A A324362 _Alois P. Heinz_, Feb 23 2019