A378190 Number of planar maps with an external face and n internal triangular faces.

1, 2, 6, 24, 100, 586, 3725, 26532, 198081, 1539550, 12274565, 99959181, 827795678, 6954099320, 59138955508, 508331799502, 4410651891166, 38590663253312, 340173195849485, 3018768835038348, 26952060900042852, 241960993507098580, 2183134755112963493, 19788571100313277286

Offset: 1

Author

Ya-Ping Lu, Nov 19 2024

Keywords

• nonn

Crossrefs

Column sums of A378103.

Cf. A002713, A169808, A377785.

Formula

a(n) = (A378337(n) + A378341(n))/2.