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 A212307 #40 Sep 23 2024 18:06:25
%S A212307 1,1,2,2,8,40,80,560,4480,4480,44800,492800,1971200,25625600,
%T A212307 358758400,1793792000,28700672000,487911424000,975822848000,
%U A212307 18540634112000,370812682240000,2595688775680000,57105153064960000,1313418520494080000,10507348163952640000
%N A212307 Numerator of n!/3^n.
%C A212307 Also the 3rd column of A152656 (or of A216919).
%F A212307 a(n) = Product_{i=1..n} A038502(i). - _Tom Edgar_, Mar 22 2014
%F A212307 a(n) = A000142(n)/A060828(n). - _Ridouane Oudra_, Sep 23 2024
%t A212307 Table[Numerator[n!/3^n], {n, 0, 32}]
%t A212307 (* or *) CoefficientList[Series[Exp[3x], {x, 0, 32}], x] // Denominator
%o A212307 (PARI) a(n) = numerator(n!/3^n); \\ _Michel Marcus_, Oct 30 2013
%Y A212307 Cf. A001316, A049606, A125824 (denominators), A152656, A216919.
%Y A212307 Cf. A000142, A060828.
%K A212307 nonn,frac
%O A212307 0,3
%A A212307 _Jean-François Alcover_ and _Paul Curtz_, Oct 30 2013