A049336 - OEIS

%I #25 Apr 18 2021 22:38:04

%S 0,0,0,0,0,0,1,0,0,0,0,1,1,1,0,0,0,0,0,1,2,3,2,1,0,0,0,0,0,0,1,3,9,13,

%T 11,5,2,0,0,0,0,0,0,0,1,4,20,49,77,75,47,16,5,0,0,0,0,0,0,0,0,1,6,40,

%U 158,406,662,737,538,259,72,14,0,0,0,0,0,0,0,0,0,1,7,70,426,1645,4176,7307,8871,7541,4353,1671,378,50

%N Table read by rows: T(n,k) = number of 2-connected planar graphs with n >= 1 nodes and 0 <= k <= 3n-6 edges.

%H Ruperto Corso, <a href="/A049336/b049336.txt">Table of n, a(n) for n = 1..249</a>

%H A. Gagarin, G. Labelle, P. Leroux, and T. Walsh, <a href="https://doi.org/10.1016/j.aam.2009.01.002">Structure and enumeration of two-connected graphs with prescribed three-connected components</a>, Adv. in Appl. Math. 43 (2009), no. 1, pp. 46-74.

%e Table begins:

%e   0;

%e   0, 0;

%e   0, 0, 0, 1;

%e   0, 0, 0, 0, 1, 1, 1;

%e   0, 0, 0, 0, 0, 1, 2, 3, 2,  1;

%e   0, 0, 0, 0, 0, 0, 1, 3, 9, 13, 11,  5,  2;

%e   0, 0, 0, 0, 0, 0, 0, 1, 4, 20, 49, 77, 75, 47, 16, 5;

%e   ...

%Y Cf. A021103, A003094, A049334.

%K nonn,tabf,easy,nice

%O 1,21

%A _Brendan McKay_

%E More terms, a(86) onwards, from Gilbert Labelle (labelle.gilbert(AT)uqam.ca), Jan 20 2009