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 A283260 #17 Oct 21 2017 20:14:16
%S A283260 1,4,1296,110075314176,1848842588950364160000000000000000,
%T A283260 27204445973673520186989292010512474445356561349778469394841600000000000000000000000000000000
%N A283260 Product of the products of elements of all the nonempty subsets of the sets of numbers from 1 to n.
%C A283260 a(7) has 237 digits.
%H A283260 N. J. A. Sloane, <a href="/A283260/b283260.txt">Table of n, a(n) for n = 1..8</a>
%F A283260 a(n) = (n!)^(2^(n-1)).
%e A283260 Rows with nonempty subsets of the sets of numbers from 1 to n:
%e A283260 {1};
%e A283260 {1}, {2}, {1, 2};
%e A283260 {1}, {2}, {3}, {1, 2}, {1, 3}, {2, 3}, {1, 2, 3};
%e A283260 ...
%e A283260 Rows with the products of elements of these subsets:
%e A283260 1;
%e A283260 1, 2, 2;
%e A283260 1, 2, 3, 2, 3, 6, 6;
%e A283260 ...
%e A283260 a(1) = (1), a(2) = (1*2*2) = 4, a(3) = (1*2*3*2*3*6*6) = 1296, ...
%o A283260 (PARI) a(n)=n!^2^(n-1) \\ _Charles R Greathouse IV_, Mar 06 2017
%Y A283260 Cf. A000225, A001788, A033312, A067174, A229338, A283261.
%K A283260 nonn,easy
%O A283260 1,2
%A A283260 _Jaroslav Krizek_, Mar 04 2017