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 A248045 #10 Apr 01 2015 08:00:57 %S A248045 1,6,120,4200,211680,13970880,1141620480,111307996800,12614906304000, %T A248045 1629845894476800,236475822507724800,38072607423743692800, %U A248045 6735922851893114880000,1299070835722243584000000,271245990498804460339200000,60962536364606302461235200000 %N A248045 (2*(n-1))! * (2*n-1)! / (n * (n-1)!^3). %C A248045 Central terms in triangles of Lah numbers: a(n) = - A008297(2*n-1,n) = A105278(2*n-1,n) = A000891(n-1)*A000142(n) = A000894(n-1)*A000142(n-1). %C A248045 a(n) = n * A204515(n-1). - _Reinhard Zumkeller_, Oct 19 2014 %H A248045 Reinhard Zumkeller, <a href="/A248045/b248045.txt">Table of n, a(n) for n = 1..250</a> %F A248045 n*a(n) = 4*(2*n-1)*(2*n-3)*a(n-1). - _R. J. Mathar_, Oct 07 2014 %o A248045 (Haskell) %o A248045 a248045 n = a000891 (n - 1) * a000142 n %Y A248045 Cf. A000142, A000891, A000894, A008297, A105278, A204515. %Y A248045 Cf. A187535 (Central Lah numbers). %K A248045 nonn %O A248045 1,2 %A A248045 _Reinhard Zumkeller_, Sep 30 2014