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 A308282 #13 Jul 27 2019 16:01:51 %S A308282 1,10,1,150,30,1,3000,900,60,1,75000,30000,3000,100,1,2250000,1125000, %T A308282 150000,7500,150,1,78750000,47250000,7875000,525000,15750,210,1, %U A308282 3150000000,2205000000,441000000,36750000,1470000,29400,280,1,141750000000,113400000000,26460000000,2646000000,132300000,3528000,50400,360,1 %N A308282 The fifth power of the unsigned Lah triangular matrix A105278. %C A308282 Also the number of k-dimensional flats of the extended Shi arrangement of dimension n consisting of hyperplanes x_i - x_j = d (1 <= i < j <= n, -4 <= d <= 5). %H A308282 N. Nakashima and S. Tsujie, <a href="https://arxiv.org/abs/1904.09748">Enumeration of Flats of the Extended Catalan and Shi Arrangements with Species</a>, arXiv:1904.09748 [math.CO], 2019. %F A308282 E.g.f.: exp(x*y/(1-5*x)). %F A308282 T(n,k) = 5^(n-k)*binomial(n-1, k-1)*n!/k! = 5^(n-k)*A105278. %e A308282 Triangle begins: %e A308282 1; %e A308282 10, 1; %e A308282 150, 30, 1; %e A308282 3000, 900, 60, 1; %e A308282 75000, 30000, 3000, 100, 1; %e A308282 ... %t A308282 Table[5^(n - k) * Binomial[n - 1, k - 1] * n! / k!, {n, 1, 10}, {k, 1, n}] // Flatten (* _Amiram Eldar_, Jul 13 2019 *) %Y A308282 Cf. A105278. %K A308282 nonn,tabl,easy %O A308282 1,2 %A A308282 _Shuhei Tsujie_, May 18 2019