A226920 - OEIS

%I #7 Dec 07 2016 23:29:51

%S 1,1,0,1,0,1,1,0,1,1,1,0,1,1,1,1,0,1,2,2,1,1,0,1,2,4,2,2,1,0,1,2,4,6,

%T 5,1,1,0,1,2,5,8,13,4,2,1,0,1,2,5,10,20,19,8,2,1,0,1,2,5,10,28,36,36,

%U 9,2

%N Array read by antidiagonals: T(n,k) = number of completely symmetric polynomials of degree k up to momentum conservation for n particles (n >= 4, k >= 0).

%H R. H. Boels, <a href="http://arxiv.org/abs/1304.7918">On the field theory expansion of superstring five point amplitudes</a>, arXiv preprint arXiv:1304.7918, 2013

%e Array begins:

%e 1,0,1,1,1,1,2,1,2,2,2,2,3,2,3,...

%e 1,0,1,1,2,2,5,4,8,9,13,15,23,24,34,...

%e 1,0,1,2,4,6,13,19,36,58,97,149,244,364,558,...

%e 1,0,1,2,4,8,20,36,83,169,344,680,1342,2518,4695,...

%e 1,0,1,2,5,10,28,59,152,364,885,2093,4930,11199,25021,...

%e 1,0,1,2,5,10,31,72,205,557,1565,4321,11942,32131,84927,...

%e 1,0,1,2,5,11,33,81,246,722,2222,6875,21497,66299,202179,...

%e ...

%Y Columns converge to A226919.

%K nonn,tabl,more

%O 4,19

%A _N. J. A. Sloane_, Jul 12 2013