A294440 - OEIS

A294440

Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = number of normalized 2n-plets, with single or double steps, associated to trees with k edges.

%I #10 Nov 21 2017 03:09:40

%S 1,2,1,4,6,1,8,25,12,1,16,90,85,20,1,32,301,476,215,30,1,64,966,2345,

%T 1722,455,42,1,128,3025,10696,11659,4928,854,56,1,256,9330,46453,

%U 71082,43779,12012,1470,72,1,512,28501,195340,404540,342642,135357,26040,2370,90,1

%N Triangle read by rows: T(n,k) (n >= 1, 1 <= k <= n) = number of normalized 2n-plets, with single or double steps, associated to trees with k edges.

%H M. Bauer and O. Golinelli, <a href="https://arxiv.org/abs/cond-mat/0007127">Random incidence matrices: Moments of the spectral density</a>, arXiv:cond-mat/0007127 [cond-mat.stat-mech], 2000-2001; J. Stat. Phys. 103, 301-307 (2001).

%e Triangle begins:

%e 1;

%e 2, 1;

%e 4, 6, 1;

%e 8, 25, 12, 1;

%e 16, 90, 85, 20, 1;

%e 32, 301, 476, 215, 30, 1;

%e 64, 966, 2345, 1722, 455, 42, 1;

%e 128, 3025, 10696, 11659, 4928, 854, 56, 1;

%e 256, 9330, 46453, 71082, 43779, 12012, 1470, 72, 1;

%e 512, 28501, 195340, 404540, 342642, 135357, 26040, 2370, 90, 1;

%e ...

%K nonn,tabl

%O 1,2

%A _N. J. A. Sloane_, Nov 20 2017