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 A380242 #9 Jan 22 2025 17:32:56 %S A380242 1,5,100,3000,110000,4550000,204000000,9690000000,480700000000, %T A380242 24667500000000,1300650000000000,70122000000000000, %U A380242 3851316000000000000,214878980000000000000,12151776800000000000000,695297229000000000000000,40193385270000000000000000,2344614140750000000000000000 %N A380242 Number of rooted 6-regular planar maps with n vertices. %H A380242 Andrew Howroyd, <a href="/A380242/b380242.txt">Table of n, a(n) for n = 0..200</a> %F A380242 a(n) = 2*10^n*(3*n)!/(n!*(2*n + 2)!). %o A380242 (PARI) a(n) = 2*10^n*(3*n)!/(n!*(2*n + 2)!) %Y A380242 Column k=3 of A380241. %Y A380242 Cf. A000168, A380243. %K A380242 nonn %O A380242 0,2 %A A380242 _Andrew Howroyd_, Jan 22 2025