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 A046674 #12 Mar 08 2020 04:14:47 %S A046674 1,18,660,42000,4142880,586776960,113020427520,28432576972800, %T A046674 9056055981772800,3562946373482496000,1697172166720622592000, %U A046674 962691052768668647424000,641260394342965606809600000,495681727573700350908825600000,440084864982859007245221888000000 %N A046674 a(n) = A046673(n)/2. %Y A046674 Cf. A000254, A049034, A046673. %K A046674 nonn %O A046674 1,2 %A A046674 _N. J. A. Sloane_ %E A046674 Offset changed to 1 by _Jon E. Schoenfield_, Mar 08 2020