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 1-9 of 9 results.

A160740 Toothpick sequence starting from a cross formed by 4 toothpicks.

Original entry on oeis.org

0, 4, 8, 16, 24, 32, 40, 56, 72, 80, 88, 104, 120, 136, 160, 200, 232, 240, 248, 264, 280, 296, 320, 360, 392, 408, 432, 472, 512, 560, 640, 744, 808, 816, 824, 840, 856, 872, 896, 936, 968, 984, 1008, 1048, 1088, 1136, 1216, 1320, 1384, 1400, 1424, 1464, 1504, 1552
Offset: 0

Views

Author

Omar E. Pol, May 25 2009

Keywords

Comments

On the infinite square grid we start at stage 0 with no toothpicks. Toothpicks have length 2. At stage 1 we place two consecutive toothpicks in the vertical direction and two consecutive toothpicks in the horizontal direction forming a cross centered at the origin. At stage 2 we place four toothpicks. At stage 3 we place eight toothpicks. For more information about the toothpick sequences see A139250. - Omar E. Pol, Nov 24 2011

Crossrefs

Formula

a(n) = 4*A160406(n).

Extensions

More terms from N. J. A. Sloane, May 25 2009

A160738 Toothpick sequence starting from a T formed by 3 toothpicks: a(n)=A160406(n)*3.

Original entry on oeis.org

0, 3, 6, 12, 18, 24, 30, 42, 54, 60, 66, 78, 90, 102, 120, 150, 174, 180, 186, 198, 210, 222, 240, 270, 294, 306, 324, 354, 384, 420, 480, 558, 606, 612, 618, 630, 642, 654, 672, 702, 726, 738, 756, 786, 816, 852, 912, 990, 1038, 1050, 1068, 1098, 1128, 1164
Offset: 0

Views

Author

Omar E. Pol, May 25 2009, Jun 19 2009

Keywords

Crossrefs

Extensions

More terms from R. J. Mathar, Jul 28 2009

A160730 Toothpick sequence starting from a right angle formed by two toothpicks.

Original entry on oeis.org

0, 2, 4, 8, 14, 20, 26, 38, 52, 64, 70, 82, 96, 112, 130, 162, 196, 216, 222, 234, 248, 264, 282, 314, 348, 372, 390, 422, 460, 504, 566, 658, 740, 776, 782, 794, 808, 824, 842, 874, 908, 932, 950, 982, 1020, 1064
Offset: 0

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

Terms after a(11) from Nathaniel Johnston, Mar 28 2011

A160158 Toothpick sequence starting from a segment of length 4 formed by two toothpicks.

Original entry on oeis.org

0, 2, 4, 8, 16, 24, 28, 36, 48, 56, 64, 80, 104, 124, 136, 156, 176, 184, 192, 208, 232, 252, 268, 296, 328, 352, 384, 440, 508, 560, 600, 652, 688, 696, 704, 720, 744, 764, 780, 808, 840, 864, 896, 952, 1020, 1072, 1116, 1176, 1224, 1248, 1280, 1336, 1404
Offset: 0

Views

Author

Omar E. Pol, May 29 2009

Keywords

Comments

The sequence gives the number of toothpicks in the sieve after n-th stage.

Crossrefs

Extensions

Extended beyond a(13) by R. J. Mathar, Jun 01 2009

A160162 a(n) = A160158(n)/2.

Original entry on oeis.org

0, 1, 2, 4, 8, 12, 14, 18, 24, 28, 32, 40, 52, 62, 68, 78, 88, 92, 96, 104, 116, 126, 134, 148, 164, 176, 192, 220, 254, 280, 300, 326, 344, 348, 352, 360, 372, 382, 390, 404, 420, 432, 448, 476, 510, 536, 558, 588, 612, 624, 640, 668, 702, 730, 760, 804, 848
Offset: 0

Views

Author

Omar E. Pol, May 29 2009

Keywords

Crossrefs

Extensions

Extended beyond a(13) by R. J. Mathar, Jun 01 2009

A160732 Toothpick sequence starting from a T formed by three toothpicks.

Original entry on oeis.org

0, 3, 6, 12, 20, 28, 34, 46, 60, 68, 76, 92, 112, 130, 148, 178, 204, 212, 220, 236, 256, 274, 294, 328, 360, 380, 408, 456, 510, 560, 620, 698, 748, 756, 764, 780, 800, 818, 838, 872, 904, 924, 952, 1000
Offset: 0

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

Terms after a(9) from Nathaniel Johnston, Mar 30 2011

A160744 a(n) = A151566(n)*3.

Original entry on oeis.org

0, 3, 6, 12, 18, 24, 30, 42, 54, 60, 66, 78, 90, 102, 114, 138, 162, 168, 174, 186, 198, 210, 222, 246, 270, 282, 294, 318, 342, 366, 390, 438, 486, 492, 498, 510, 522, 534, 546, 570, 594, 606, 618, 642, 666, 690, 714, 762, 810, 822, 834, 858, 882, 906, 930
Offset: 0

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

More terms from R. J. Mathar, Jul 28 2009

A160742 a(n) = A151566(n)*2.

Original entry on oeis.org

0, 2, 4, 8, 12, 16, 20, 28, 36, 40, 44, 52, 60, 68, 76, 92, 108, 112, 116, 124, 132, 140, 148, 164, 180, 188, 196, 212, 228, 244, 260, 292, 324, 328, 332, 340, 348, 356, 364, 380, 396, 404, 412, 428, 444, 460, 476, 508, 540, 548, 556, 572, 588, 604, 620, 652, 684
Offset: 0

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

More terms from Jinyuan Wang, Mar 14 2020

A160746 a(n) = A151566(n)*4.

Original entry on oeis.org

0, 4, 8, 16, 24, 32, 40, 56, 72, 80, 88, 104, 120, 136, 152, 184, 216, 224, 232, 248, 264, 280, 296, 328, 360, 376, 392, 424, 456, 488, 520, 584, 648, 656, 664, 680, 696, 712, 728, 760, 792, 808, 824, 856, 888, 920, 952, 1016, 1080, 1096, 1112, 1144, 1176, 1208, 1240
Offset: 0

Views

Author

Omar E. Pol, May 25 2009

Keywords

Crossrefs

Extensions

More terms from N. J. A. Sloane, May 25 2009
Showing 1-9 of 9 results.