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 A372723 #7 May 21 2024 10:20:05 %S A372723 1,0,1,1,2,2,2,9,12,6,9,44,84,72,24,44,265,640,780,480,120,265,1854, %T A372723 5430,8520,7560,3600,720,1854,14833,50988,97650,112560,78120,30240, %U A372723 5040,14833,133496,526568,1189104,1681680,1525440,866880,282240,40320 %N A372723 Triangle read by rows: Column k has e.g.f. t^k / ((1 - t)^(k + 1) * exp(t)). %e A372723 Triangle starts: %e A372723 [0] 1; %e A372723 [1] 0, 1; %e A372723 [2] 1, 2, 2; %e A372723 [3] 2, 9, 12, 6; %e A372723 [4] 9, 44, 84, 72, 24; %e A372723 [5] 44, 265, 640, 780, 480, 120; %e A372723 [6] 265, 1854, 5430, 8520, 7560, 3600, 720; %e A372723 [7] 1854, 14833, 50988, 97650, 112560, 78120, 30240, 5040; %e A372723 [8] 14833, 133496, 526568, 1189104, 1681680, 1525440, 866880, 282240, 40320; %p A372723 MAX := 14; gf := k -> t^k / ((1 - t)^(k + 1) * exp(t)): %p A372723 ser := k -> series(gf(k), t, MAX): %p A372723 col := k -> local n; seq(n!*coeff(series(ser(k), t, MAX-1), t, n), n = 0..MAX-2): %p A372723 T := (n, k) -> col(k)[n+1]: %p A372723 seq(lprint(seq(T(n, k), k = 0..n)), n = 0..8); %Y A372723 Cf. A000166 (column 0), A000142 (main diagonal), A062119 (subdiagonal), A000354 (row sums), A033999 (alternating row sums), A372716 (central terms). %K A372723 nonn,tabl %O A372723 0,5 %A A372723 _Peter Luschny_, May 21 2024