A358746 -id:A358746 - cp's OEIS frontend

A370979 Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of edges in H_n.

1, 4, 21, 20, 135, 144, 553, 440, 1575, 1460, 3729, 3132, 7527, 6888, 13605, 12016, 23307, 20988, 36385, 32420, 54915, 51216, 79741, 70776, 113175, 105300, 154845, 144508, 206799, 195840, 272893, 255840, 352275, 335036, 446845, 422820, 561031, 534736, 695877, 659480, 850463, 815724

Offset: 1

Scott R. Shannon and N. J. A. Sloane, Mar 25 2024

nonn

For the numbers of vertices and regions in G_n see A358746 and A370978.

H_n is the union of the graph G_n defined in A370976 and the polygon through the initial n points.

Cf. A358746, A358782, A358783, A370976, A370977, A370978.

a(n) = A358783(n) if n even, a(n) = A358783(n) + n if n odd.

a(n) = A358783(n) + n if n even, a(n) = A358783(n) + 3*n if n odd.

A373106 Number of vertices among all distinct circles that can be constructed from the 4 vertices and the equally spaced 4n points placed on the sides of a square when every pair of the 4 + 4n points are connected by a circle and where the points lie at the ends of the circle's diameter.

Original entry on oeis.org

5, 61, 677, 2533, 7705, 17269, 37161, 65089, 111877, 174545, 274213

Offset: 0

Scott R. Shannon, May 25 2024

A circle is constructed for every pair of the 4 + 4*n points, the two points lying at the ends of a diameter of the circle.

Scott R. Shannon, Image for n = 0. In this and other images the 4 + 4*n vertices forming the square are drawn larger for clarity.
Scott R. Shannon, Image for n = 1.
Scott R. Shannon, Image for n = 2.
Scott R. Shannon, Image for n = 3.

Cf. A373107 (regions), A373108 (edges), A373109 (k-gons), A373110 (circles), A372977, A372731, A358746, A362233, A360351.

a(n) = A373108(n) - A373107(n) + 1 by Euler's formula.

A370978 Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of regions in H_n.

Original entry on oeis.org

1, 3, 16, 16, 81, 91, 302, 272, 829, 831, 1926, 1752, 3849, 3739, 6916, 6464, 11799, 11143, 18374, 17180, 27679, 26819, 40136, 37200, 56901, 54679, 77788, 74816, 103821, 101071, 136928, 131776, 176683, 172143, 224036, 216936, 281201, 273867, 348700, 337520, 426073, 416683

Offset: 1

Scott R. Shannon and N. J. A. Sloane, Mar 25 2024

nonn

H_n is the union of the graph G_n defined in A370976 and the polygon through the initial n points.

Scott R. Shannon, Image for n = 3.
Scott R. Shannon, Image for n = 5.

Cf. A358746, A358782, A358783, A370976, A370977, A370979.

a(n) = A358782(n) + n if n even, a(n) = A358782(n) + 3*n if n odd.

A371377 Irregular table read by rows: place n equally spaced 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.

Original entry on oeis.org

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

Scott R. Shannon, Mar 20 2024

See A371373 and A371374 for images of the graphs.

			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;
.
.

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

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

cp's OEIS Frontend

A370979 Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of edges in H_n.

Views

Author

Keywords

Comments

Crossrefs

Formula

A373106 Number of vertices among all distinct circles that can be constructed from the 4 vertices and the equally spaced 4n points placed on the sides of a square when every pair of the 4 + 4n points are connected by a circle and where the points lie at the ends of the circle's diameter.

Views

Author

Keywords

Comments

Links

Crossrefs

Formula

A370978 Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of regions in H_n.

Views

Author

Keywords

Comments

Links

Crossrefs

Formula

Views

Author

Keywords

Comments

Examples

Crossrefs

Formula

cp's OEIS Frontend

A370979 Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of edges in H_n.

Views

Author

Keywords

Comments

Crossrefs

Formula

A373106 Number of vertices among all distinct circles that can be constructed from the 4 vertices and the equally spaced 4*n points placed on the sides of a square when every pair of the 4 + 4*n points are connected by a circle and where the points lie at the ends of the circle's diameter.

Views

Author

Keywords

Comments

Links

Crossrefs

Formula

A370978 Draw a regular n-gon and the enclosing circle, then for each pair of vertices X, Y, draw a circle with diameter XY; the union of these figures is the graph H_n; sequence gives number of regions in H_n.

Views

Author

Keywords

Comments

Links

Crossrefs

Formula

Views

Author

Keywords

Comments

Examples

Crossrefs

Formula

A373106 Number of vertices among all distinct circles that can be constructed from the 4 vertices and the equally spaced 4n points placed on the sides of a square when every pair of the 4 + 4n points are connected by a circle and where the points lie at the ends of the circle's diameter.