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 A371995 #9 Apr 25 2024 13:23:09 %S A371995 1,1,1,0,1,0,1,0,1,1,0,3,1,0,6,2,1,0,10,8,1,0,15,20,9,1,0,21,40,45,1, %T A371995 0,28,70,135,44,1,0,36,112,315,264,1,0,45,168,630,924,265,1,0,55,240, %U A371995 1134,2464,1855,1,0,66,330,1890,5544,7420,1854,1,0,78,440,2970,11088,22260,14832 %N A371995 Triangle read by rows: T(n, k) = binomial(n - k, k) * subfactorial(k), for n >= 0 and 0 <= k <= floor(n/2). %F A371995 T(n, k) = A011973(n, k) * A000166(k). %F A371995 The rows are the antidiagonals of A098825. %e A371995 Triangle starts: %e A371995 [0] 1; %e A371995 [1] 1; %e A371995 [2] 1, 0; %e A371995 [3] 1, 0; %e A371995 [4] 1, 0, 1; %e A371995 [5] 1, 0, 3; %e A371995 [6] 1, 0, 6, 2; %e A371995 [7] 1, 0, 10, 8; %e A371995 [8] 1, 0, 15, 20, 9; %e A371995 [9] 1, 0, 21, 40, 45; %t A371995 T[n_, k_] := Binomial[n - k, k] * Subfactorial[k]; %t A371995 Table[T[n, k], {n, 0, 9}, {k, 0, n/2}] // MatrixForm %Y A371995 Cf. A000166, A011973, A098825, A372102 (row sums), A371998 (main diagonal). %K A371995 nonn,tabf %O A371995 0,12 %A A371995 _Peter Luschny_, Apr 24 2024