A280785 Triangle read by rows: numbers of nonintersecting circles, one marked.

1, 1, 1, 2, 2, 1, 5, 5, 2, 1, 13, 13, 6, 2, 1, 35, 35, 16, 6, 2, 1, 95, 95, 46, 17, 6, 2, 1, 262, 262, 128, 49, 17, 6, 2, 1, 727, 727, 364, 139, 50, 17, 6, 2, 1, 2033, 2033, 1029, 401, 142, 50, 17, 6, 2, 1, 5714, 5714, 2930, 1147, 412, 143, 50, 17, 6, 2, 1, 16136, 16136, 8344, 3299, 1184, 415, 143, 50, 17, 6, 2, 1

Offset

1,4

Links

Table of n, a(n) for n=1..78.

R. J. Mathar, Topologically Distinct Sets of Non-intersecting Circles in the Plane, arXiv:1603.00077 [math.CO], 2016.

Example

Triangle begins:
1,
1,1,
2,2,1,
5,5,2,1,
13,13,6,2,1,
35,35,16,6,2,1,
95,95,46,17,6,2,1,
262,262,128,49,17,6,2,1,
727,727,364,139,50,17,6,2,1,
...

Crossrefs

Row sums are A000107.

Sequence in context: A210879 A176265 A187307 * A204851 A114292 A333724

Adjacent sequences: A280782 A280783 A280784 * A280786 A280787 A280788

Keyword

nonn,tabl

Author

N. J. A. Sloane, Jan 20 2017

Status

approved