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.

Previous Showing 11-16 of 16 results.

A160714 T-toothpick sequence starting at the corner of an infinite square, but with angle = Pi/4.

Original entry on oeis.org

0, 1, 2, 5, 6, 9, 12, 21, 22, 25, 28, 37, 40, 49, 58, 85, 112, 113
Offset: 0

Views

Author

Omar E. Pol, Jun 02 2009

Keywords

Comments

The sequence gives the number of T-toothpicks after n rounds.
See A160172 for more information about T-toothpick sequences.

Crossrefs

A160724 a(n) = A160714(n)*3.

Original entry on oeis.org

0, 3, 6, 15, 18, 27, 36, 63, 66, 75, 84, 111, 120, 147, 174, 255, 336, 339
Offset: 0

Views

Author

Omar E. Pol, Jun 02 2009

Keywords

Comments

The sequence gives the number of T-toothpicks in the structure after n rounds.
See A160172 and A160714 for more information about T-toothpick sequences.

Crossrefs

Extensions

a(9)-a(17) from 3*A160714(n) by Jinyuan Wang, Mar 14 2020

A160726 a(n) = A160714(n)*4.

Original entry on oeis.org

0, 4, 8, 20, 24, 36, 48, 84, 88, 100, 112, 148, 160, 196, 232, 340, 448, 452
Offset: 0

Views

Author

Omar E. Pol, Jun 02 2009

Keywords

Comments

The sequence gives the number of T-toothpicks in the structure after n rounds.
See A160172 and A160714 for more information about T-toothpick sequences.

Crossrefs

Extensions

a(9)-a(17) from 4*A160714(n) by Jinyuan Wang, Mar 14 2020

A183127 Number of toothpicks added at n-th stage to the toothpick structure of A183126.

Original entry on oeis.org

0, 1, 6, 16, 16, 40, 16, 40, 40, 112, 16, 40, 40, 112, 40, 112, 112, 328, 16, 40, 40, 112, 40, 112, 112, 328, 40, 112, 112, 328, 112, 328, 328, 976, 16, 40, 40, 112, 40, 112, 112, 328, 40, 112, 112, 328, 112, 328, 328, 976, 40, 112, 112, 328, 112, 328, 328, 976
Offset: 0

Views

Author

Omar E. Pol, Mar 28 2011

Keywords

Comments

Essentially the first differences of A183126.

Crossrefs

Programs

  • Mathematica
    a[n_] := 4*(1 + 3^DigitCount[n-2, 2, 1]); a[0] = 0; a[1] = 1; a[2] = 6; Array[a, 100, 0] (* Amiram Eldar, Aug 01 2023 *)

Formula

a(n) = 4*(1 + 3^A000120(n-2)), n >= 3. - Nathaniel Johnston, Apr 06 2011

Extensions

a(0)-a(10) confirmed and a(11)-a(35) added by John W. Layman, Mar 30 2011
a(36)-a(47) from Nathaniel Johnston, Apr 06 2011
More terms from Amiram Eldar, Aug 01 2023

A183149 Number of toothpicks added at n-th stage to the toothpick structure of A183148.

Original entry on oeis.org

0, 1, 3, 9, 9, 21, 9, 21, 21, 57, 9, 21, 21, 57, 21, 57, 57, 165, 9, 21, 21, 57, 21, 57, 57, 165, 21, 57, 57, 165, 57, 165, 165, 489, 9, 21, 21, 57, 21, 57, 57, 165, 21, 57, 57, 165, 57, 165, 165, 489, 21, 57, 57, 165, 57, 165
Offset: 0

Views

Author

Omar E. Pol, Mar 28 2011, Apr 02 2011

Keywords

Comments

Essentially the first differences of A183148.

Examples

			If written as a triangle begins:
0,
1,
3,
9,
9,21,
9,21,21,57,
9,21,21,57,21,57,57,165,
9,21,21,57,21,57,57,165,21,57,57,165,57,165,165,489,
		

Crossrefs

Formula

a(n) = 3*A183061(n-1), for n >=2

A160716 a(n) = A160714(n)*2.

Original entry on oeis.org

0, 2, 4, 10, 12, 18, 24, 42, 44, 50, 56, 74, 80, 98, 116, 170, 224, 226
Offset: 0

Views

Author

Omar E. Pol, Jun 02 2009

Keywords

Comments

The sequence gives the number of T-toothpicks in the structure after n rounds.
See A160172 and A160714 for more information about T-toothpick sequences.

Crossrefs

Previous Showing 11-16 of 16 results.