A226920 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).

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, 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, 9, 2

Offset

4,19

Links

Table of n, a(n) for n=4..69.

R. H. Boels, On the field theory expansion of superstring five point amplitudes, arXiv preprint arXiv:1304.7918, 2013

Example

Array begins:
1,0,1,1,1,1,2,1,2,2,2,2,3,2,3,...
1,0,1,1,2,2,5,4,8,9,13,15,23,24,34,...
1,0,1,2,4,6,13,19,36,58,97,149,244,364,558,...
1,0,1,2,4,8,20,36,83,169,344,680,1342,2518,4695,...
1,0,1,2,5,10,28,59,152,364,885,2093,4930,11199,25021,...
1,0,1,2,5,10,31,72,205,557,1565,4321,11942,32131,84927,...
1,0,1,2,5,11,33,81,246,722,2222,6875,21497,66299,202179,...
...

Crossrefs

Columns converge to A226919.

Sequence in context: A327747 A282750 A265890 * A362759 A123736 A358476

Adjacent sequences: A226917 A226918 A226919 * A226921 A226922 A226923

Keyword

nonn,tabl,more

Author

N. J. A. Sloane, Jul 12 2013

Status

approved