OFFSET
1,5
COMMENTS
These are Betti numbers [Dochtermann]. - N. J. A. Sloane, Dec 02 2015
Number of terms in row n is A000041(n).
Row sums generate sequence A000085: 1, 2, 4, 10, 26, 76, ...
Sum of squares generates A000142; e.g., -1*1 + 4*4 + 6*6 + 4*4 + 1*1 + 5*5 +5*5 = 5! = 120.
LINKS
A. Dochtermann, Face rings of cycles, associahedra, and standard Young tableaux, arXiv preprint arXiv:1503.06243 [math.CO], 2015-2016.
EXAMPLE
A059797 begins 2, 5, 5, 9, 16, 9, so row six of this sequence begins 1, 5, 10, 10, 5, 1, 9, 16, 9, ...
Triangle begins:
1;
1, 1;
1, 2, 1;
1, 3, 3, 1, 2;
1, 4, 6, 4, 1, 5, 5;
1, 5, 10, 10, 5, 1, 9, 16, 9, 5, 5;
1, 6, 15, 20, 15, 6, 1, 14, 35, 35, 14, 14, 21, 21, 14;
1, 7, 21, 35, 35, 21, 7, 1, 20, 64, 90, 64, 20, 28, 70, 56, 56, 70, 28, 14, 42, 14;
CROSSREFS
KEYWORD
nice,nonn,tabf
AUTHOR
Alford Arnold, Mar 04 2002
STATUS
approved