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 A318255 #13 Mar 28 2020 05:29:42 %S A318255 1,1,1,1,10,-9,1,28,-504,477,1,55,-4158,78705,-74601,1,91,-18018, %T A318255 1432431,-27154764,25740261,1,136,-55692,11595870,-923261976, %U A318255 17503377480,-16591655817,1,190,-139536,60087690,-12529983960,997692516360,-18914487631380,17929265150637 %N A318255 Associated Omega numbers of order 3, triangle T(n,k) read by rows for n >= 0 and 0 <= k <= n. %C A318255 See the comments in A318254. %F A318255 T(m, n, k) = binomial(m*n-1, m*(n-k))*A318253(m, k) for k>0 and 1 for k=0. We consider here the case m=3. %e A318255 Triangle starts: %e A318255 [0] 1 %e A318255 [1] 1, 1 %e A318255 [2] 1, 10, -9 %e A318255 [3] 1, 28, -504, 477 %e A318255 [4] 1, 55, -4158, 78705, -74601 %e A318255 [5] 1, 91, -18018, 1432431, -27154764, 25740261 %e A318255 [6] 1, 136, -55692, 11595870, -923261976, 17503377480, -16591655817 %p A318255 # The function TNum is defined in A318253. %p A318255 T := (m, n, k) -> `if`(k=0, 1, binomial(m*n-1, m*(n-k))*TNum(m, k)): %p A318255 for n from 0 to 6 do seq(T(3, n, k), k=0..n) od; %o A318255 (Sage) # uses[AssociatedOmegaNumberTriangle from A318254] %o A318255 A318255Triangle = lambda dim: AssociatedOmegaNumberTriangle(3, dim) %o A318255 print(A318255Triangle(8)) %Y A318255 T(n, 0) = A060544, T(n, n) = A293951(n+1) (up to signs), row sums are A040000. %Y A318255 Cf. A318146, A318253, A318254 (m=2). %K A318255 sign,tabl %O A318255 0,5 %A A318255 _Peter Luschny_, Aug 26 2018