A371377 Irregular table read by rows: place n equally space points around the circumference of a circle and then, for each pair of points, draw two distinct circles, whose radii are the same as the first circle, such that both points lie on their circumferences. T(n,k), k>=2, gives the number of vertices formed by the crossing of k arcs.

0, 0, 0, 4, 0, 4, 10, 10, 0, 5, 6, 6, 0, 6, 1, 98, 35, 0, 0, 0, 7, 104, 32, 0, 0, 0, 8, 369, 81, 0, 0, 0, 0, 0, 10, 410, 80, 0, 0, 0, 0, 0, 10, 1034, 165, 0, 0, 0, 0, 0, 0, 0, 11, 768, 84, 0, 0, 36, 0, 0, 0, 0, 12, 1, 2288, 286, 0, 0, 0, 0, 0, 0, 0, 0, 0, 13, 2464, 280, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14

Offset

1,4

Comments

See A371373 and A371374 for images of the graphs.

Links

Table of n, a(n) for n=1..88.

Formula

Sum of row(n) = A371373(n).

Example

The table begins:
0;
0;
0, 4;
0, 4;
10, 10, 0, 5;
6, 6, 0, 6, 1;
98, 35, 0, 0, 0, 7;
104, 32, 0, 0, 0, 8;
369, 81, 0, 0, 0, 0, 0, 10;
410, 80, 0, 0, 0, 0, 0, 10;
1034, 165, 0, 0, 0, 0, 0, 0, 0, 11;
768, 84, 0, 0, 36, 0, 0, 0, 0, 12, 1;
2288, 286, 0, 0, 0, 0, 0, 0, 0, 0, 0, 13;
2464, 280, 0, 0, 0, 0, 0, 0, 0, 0, 0, 14;
4230, 420, 0, 30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16;
4672, 448, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16;
7990, 680, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 17;
7254, 450, 0, 0, 108, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 18, 1;
13148, 969, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 19;
13620, 960, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 20;
20265, 1323, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 22;
21230, 1320, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 22;
30452, 1771, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 23;
29376, 1416, 0, 0, 216, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 24, 1;
43800, 2300, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 25;
45136, 2288, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 26;
.
.

Crossrefs

Cf. A371373 (vertices), A371374 (regions), A371375 (edges), A371376 (k-gons), A371264, A335102, A007569, A358746, A331702.

Sequence in context: A209134 A281297 A058536 * A154854 A151672 A058493

Adjacent sequences: A371374 A371375 A371376 * A371378 A371379 A371380

Keyword

nonn,tabf

Author

Scott R. Shannon, Mar 20 2024

Status

approved