cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Showing 1-10 of 11 results. Next

A331931 The number of regions inside a hexagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Original entry on oeis.org

24, 408, 2268, 8208, 20832, 44640, 89214, 154752, 249906, 390012, 590658, 824712, 1183704, 1580868, 2067162, 2770476, 3585582, 4397172, 5665818, 6827736, 8318976, 10209948, 12364098, 14395164, 17194230, 20216808, 23436612, 27124416, 31817676, 35516328
Offset: 1

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Author

Keywords

Comments

The terms are from numeric computation - no formula for a(n) is currently known.

Crossrefs

Cf. A331932 (n-gons), A330845 (edges), A330846 (vertices), A007678, A092867, A331452, A331929.

Extensions

a(9)-a(30) from Lars Blomberg, May 12 2020

A330846 The number of vertices inside a hexagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Original entry on oeis.org

19, 301, 1753, 6913, 17713, 38497, 80473, 139927, 225595, 356329, 549967, 756901, 1113283, 1474867, 1913365, 2620789, 3418081, 4119175, 5428993, 6453235, 7861957, 9761335, 11913115, 13695055, 16489633, 19439797, 22464883, 25997329, 30860593, 33866305
Offset: 1

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Author

Keywords

Comments

See the links in A331931 for images of the hexagons.

Crossrefs

Cf. A331931 (regions), A331932 (n-gons), A330845 (edges), A092866, A332599, A007569.

Extensions

a(9)-a(30) from Lars Blomberg, May 12 2020

A329710 The number of edges inside a pentagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Original entry on oeis.org

20, 290, 2215, 7405, 21150, 43490, 88230, 151135, 250825, 384360, 578840, 814180, 1151525, 1550530, 2063225, 2676925, 3452460, 4333340, 5436210, 6668320, 8154980, 9837690, 11822175, 13993360, 16569650, 19401865, 22636495, 26182350, 30253225, 34608450, 39628050
Offset: 1

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Author

Keywords

Comments

See the links in A331929 for images of the pentagons.

Crossrefs

Cf. A331929 (regions), A331939 (n-gons), A330847 (vertices), A330845, A274586, A332600, A331765.

Extensions

a(9) and beyond from Lars Blomberg, May 11 2020

A331932 Triangle read by rows: Take a hexagon with all diagonals drawn, as in A331931. Then T(n,k) = number of k-sided polygons in that figure for k = 3, 4, ..., n+4.

Original entry on oeis.org

18, 6, 0, 264, 108, 36, 0, 1344, 654, 252, 12, 6, 4164, 2772, 1020, 228, 24, 0, 10038, 7758, 2424, 516, 72, 24, 0, 21108, 16188, 6060, 1128, 156, 0, 0, 0, 39690, 32022, 13368, 3654, 432, 48, 0, 0, 0, 68052, 56616, 22980, 6084, 888, 120, 12, 0, 0, 0
Offset: 1

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Author

Keywords

Comments

See the links in A331931 for images of the hexagons.

Examples

			A hexagon with no other points along its edges, n = 1, contains 18 triangles, 6 quadrilaterals and no other n-gons, so the first row is [18,6,0]. A hexagon with 1 point dividing its edges, n = 2, contains 264 triangles, 108 quadrilaterals, 36 pentagons and no other n-gons, so the second row is [264,108,36,0].
Triangle begins:
  18,6,0
  264,108,36,0
  1344,654,252,12,6
  4164,2772,1020,228,24,0
  10038,7758,2424,516,72,24,0
  21108,16188,6060,1128,156,0,0,0
  39690,32022,13368,3654,432,48,0,0,0
  68052,56616,22980,6084,888,120,12,0,0,0
The row sums are A331931.
		

Crossrefs

Cf. A331931 (regions), A330845 (edges), A330846 (vertices), A331906, A007678, A092867, A331452.

A332419 The number of edges on a decagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Original entry on oeis.org

390, 7800, 48870, 164470, 430840, 900890, 1735800, 2982660, 4849740, 7438490, 11017860, 15596420, 21713060, 29254830, 38714410, 50238450, 64311090, 80839300, 100786890, 123786030, 150835530
Offset: 1

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Author

Keywords

Comments

See the links in A333139 for images of the decagons.

Crossrefs

Cf. A333139 (regions), A332417 (n-gons), A332418 (vertices), A330845, A274586, A332600, A331765.

Extensions

a(6)-a(21) from Lars Blomberg, May 18 2020

A332429 The number of edges on a nonagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Original entry on oeis.org

288, 5148, 33291, 108252, 283464, 591723, 1133928, 1941786, 3166605, 4837824, 7170120, 10164258, 14124447, 19017180, 25206777, 32659191, 41826366, 52595622, 65549880, 80507142, 98143200, 118271898, 141655707
Offset: 1

Views

Author

Keywords

Comments

See the links in A332421 for images of the nonagons.

Crossrefs

Cf. A332421 (regions), A332427 (n-gons), A332428 (vertices), A330845, A274586, A332600, A331765.

Extensions

a(6)-a(23) from Lars Blomberg, May 16 2020

A333110 The number of edges on an octagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Original entry on oeis.org

136, 2632, 17728, 60672, 163776, 341920, 673112, 1155144, 1892528, 2905088, 4327912, 6104696, 8557008, 11532288, 15271624, 19829528, 25447640, 31957872, 39935984, 49008392, 59807600, 72151536, 86465832, 102403360
Offset: 1

Views

Author

Keywords

Comments

See the links in A333075 for images of the octagons.

Crossrefs

Cf. A333075 (regions), A333076 (n-gons), A333109 (vertices), A330845, A274586 , A332600, A331765.

Extensions

a(7)-a(24) from Lars Blomberg, May 14 2020

A333112 The number of edges inside a heptagon formed by the straight line segments mutually connecting all vertices and all points that divide the sides into n equal parts.

Original entry on oeis.org

91, 1575, 10962, 35812, 96257, 201054, 389991, 668458, 1096508, 1675835, 2494989, 3536876, 4930408, 6639913, 8816458, 11425631, 14659085, 18433975, 23007579, 28257418, 34478871, 41557817, 49822388, 59079475, 69756253, 81641812, 95165210
Offset: 1

Views

Author

Keywords

Comments

See the links in A329713 for images of the heptagons.

Crossrefs

Cf. A329713 (regions), A329714 (n-gons), A333113 (vertices), A330845, A274586 , A332600, A331765.

Extensions

a(8)-a(27) from Lars Blomberg, May 13 2020

A335735 a(n) is the number of edges formed by n-secting the angles of a hexagon.

Original entry on oeis.org

6, 12, 126, 42, 366, 318, 762, 432, 1278, 1152, 1950, 1338, 2658, 2550, 3642, 2808, 4590, 4500, 5898, 4734, 7086, 6978, 8706, 7344, 10134, 9876, 12066, 10422, 13710, 13374, 15930, 14052, 17850, 17460, 20298, 18222, 22494, 22062, 25206, 22860, 27642, 27216
Offset: 1

Views

Author

Lars Blomberg, Jun 21 2020

Keywords

Crossrefs

Cf. A330845 (n-sected sides, not angles), A335733 (regions), A335734 (vertices), A335736 (ngons).

A357198 Number of edges in a hexagon when n internal hexagons are drawn between the 6n points that divide each side into n+1 equal parts.

Original entry on oeis.org

6, 18, 54, 114, 198, 306, 438, 594, 774, 942, 1206, 1422, 1734, 2034, 2310, 2706, 3078, 3474, 3894, 4242, 4806, 5298, 5814, 6186, 6918, 7506, 8118, 8706, 9414, 9978, 10806, 11538, 12258, 13074, 13842, 14562, 15558, 16434, 17298, 17970, 19206, 20082, 21174, 22122, 23154, 24306, 25398, 26286
Offset: 0

Views

Author

Scott R. Shannon, Sep 17 2022

Keywords

Comments

Unlike similar dissections of the triangle and square, see A357008 and A357061, there is no obvious pattern for n values that yield hexagons with non-simple intersections; these n values begin 9, 11, 14, 19, 23, 27, 29, 32, 34, 35, 38, 39, 41, 43, ... .

Crossrefs

Cf. A357196 (regions), A357197 (vertices), A330845, A357008 (triangle), A357061 (square).

Formula

a(n) = A357196(n) + A357197(n) - 1 by Euler's formula.
Conjecture: a(n) = 12*n^2 + 6 for hexagons that only contain simple intersections when cut by n internal hexagons.
Showing 1-10 of 11 results. Next