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 A178842 #17 Sep 08 2022 08:45:54 %S A178842 0,0,4,126,4368,177100,8347680,450978066,27540584512,1878392407320, %T A178842 141629804643600,11703541346076580,1052134368066259632, %U A178842 102250849636865496528,10683770265451303535424,1194448077521704400002650,142288257910903254700704000,17993390003427864738863790640 %N A178842 a(n) = binomial((n-1)^2, n). %C A178842 Number of ways to place n objects in an (n-1) X (n-1) array (e.g., the number of ways to arrange stars in a flag's field pattern). %H A178842 G. C. Greubel, <a href="/A178842/b178842.txt">Table of n, a(n) for n = 1..250</a> %t A178842 a[n_] := Binomial[(n - 1)^2, n]; Array[a, 18] (* _Robert G. Wilson v_, Jul 25 2010 *) %o A178842 (PARI) vector(20, n, binomial((n-1)^2,n)) \\ _G. C. Greubel_, Jan 21 2019 %o A178842 (Magma) [Binomial((n-1)^2,n): n in [1..20]]; // _G. C. Greubel_, Jan 21 2019 %o A178842 (Sage) [binomial((n-1)^2,n) for n in (1..20)] # _G. C. Greubel_, Jan 21 2019 %o A178842 (GAP) List([1..20], n -> Binomial((n-1)^2, n)); # _G. C. Greubel_, Jan 21 2019 %Y A178842 Cf. A014062 (binomial(n^2, n)). %K A178842 nonn %O A178842 1,3 %A A178842 _Thomas Young_, Jun 17 2010