A366039 - OEIS

%I #21 Nov 19 2023 01:56:43

%S 1,2,2,2,1,2,5,9,12,8,5,1,3,7,21,43,75,89,81,42,17,1,3,11,34,100,239,

%T 492,784,1002,926,632,260,71

%N Irregular triangle read by rows: T(n,k) = number of cells of dimension k in the moduli space of tropical curves of genus n.

%C Row n has 3n + 1 entries, for 0 <= k <= 3n.

%H Melody Chan, <a href="http://dx.doi.org/10.2140/ant.2012.6.1133">Combinatorics of the tropical Torelli map</a>, Algebra Number Theory, 6 (2012), 1133-1169.

%e The irregular triangle T(n,k) begins:

%e n\k  0   1   2   3    4    5    6    7     8    9   10   11  12...

%e 2:   1,  2,  2,  2;

%e 3:   1,  2,  5,  9,  12,   8,   5;

%e 4:   1,  3,  7, 21,  43,  75,  89,  81,   42,  17;

%e 5:   1,  3, 11, 34, 100, 239, 492, 784, 1002, 926, 632, 260, 71;

%e ...

%Y Last entry in each row is A005967.

%Y Row sums are A174224.

%K nonn,tabf,more

%O 2,2

%A _Harry Richman_, Oct 23 2023