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 A378190 #5 Dec 12 2024 23:15:51 %S A378190 1,2,6,24,100,586,3725,26532,198081,1539550,12274565,99959181, %T A378190 827795678,6954099320,59138955508,508331799502,4410651891166, %U A378190 38590663253312,340173195849485,3018768835038348,26952060900042852,241960993507098580,2183134755112963493,19788571100313277286 %N A378190 Number of planar maps with an external face and n internal triangular faces. %F A378190 a(n) = (A378337(n) + A378341(n))/2. %Y A378190 Column sums of A378103. %Y A378190 Cf. A002713, A169808, A377785. %K A378190 nonn %O A378190 1,2 %A A378190 _Ya-Ping Lu_, Nov 19 2024