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 A073888 #6 May 18 2020 04:04:07
%S A073888 1,2,4,32,262144,38685626227668133590597632
%N A073888 a(1) = 1, a(2) = 2; a(n+1) = a(n)^n/a(n-1).
%F A073888 a(n) = 2^A058798(n).
%p A073888 A073888:= proc(n) option remember;
%p A073888 if n<3 then n;
%p A073888 else a(n-1)^(n-1)/a(n-2);
%p A073888 fi; end;
%p A073888 seq(A073888(n), n = 1..7); # _G. C. Greubel_, May 17 2020
%t A073888 a[n_]:= a[n]= If[n<3, n, a[n-1]^(n-1)/a[n-2]]; Table[a[n], {n, 7}] (* _G. C. Greubel_, May 17 2020 *)
%o A073888 (Magma)
%o A073888 I:=[1,2]; [n le 2 select I[n] else Self(n-1)^(n-1)/Self(n-2): n in [1..7]]; // _G. C. Greubel_, May 17 2020
%o A073888 (Sage)
%o A073888 def a(n):
%o A073888 if (n<3): return n
%o A073888 else: return a(n-1)^(n-1)/a(n-2)
%o A073888 [a(n) for n in (1..7)] # _G. C. Greubel_, May 17 2020
%Y A073888 Cf. A058798, A073889.
%K A073888 nonn
%O A073888 1,2
%A A073888 _Amarnath Murthy_, Aug 17 2002