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.

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A160796 Total number of "ON" cells at n-th stage in simple 2-dimensional cellular automaton which is the "corner" structure corresponding to A160118.

Original entry on oeis.org

0, 1, 8, 11, 32, 35, 56, 65, 128, 131, 152, 161, 224, 233, 296, 323, 512, 515, 536, 545, 608, 617, 680, 707, 896, 905, 968, 995, 1184, 1211, 1400, 1481, 2048, 2051, 2072, 2081, 2144, 2153, 2216, 2243, 2432, 2441, 2504, 2531, 2720, 2747, 2936, 3017, 3584, 3593, 3656
Offset: 0

Views

Author

Omar E. Pol, Jun 13 2009, Jun 14 2009

Keywords

Comments

This bears the same relationship to A160118 as A153006 does to A139250.

Examples

			If we label the generations of cells turned ON by consecutive numbers we get the cell pattern shown below:
..9...............9
...888.888.888.888.
...878.878.878.878.
...8866688.8866688.
.....656.....656...
...8866444.4446688.
...878.434.434.878.
...888.4422244.888.
.........212.......
00000000002244.888.
0000000000.434.878.
0000000000.4446688.
0000000000...656...
0000000000.8866688.
0000000000.878.878.
0000000000.888.888.
0000000000........9
0000000000.........
0000000000.........
		

Crossrefs

Programs

  • Mathematica
    With[{d = 2}, wt[n_] := DigitCount[n, 2, 1]; a[n_] := (5 + 3 * If[OddQ[n], 3^d + (2^d)*Sum[(2^d - 1)^(wt[k] - 1), {k, 1, (n - 1)/2}] + (2^d)*(3^d - 2)*Sum[(2^d - 1)^(wt[k] - 1), {k, 1, (n - 3)/2}], 3^d + (2^d)*Sum[(2^d - 1)^(wt[k] - 1), {k, 1, n/2 - 1}] + (2^d)*(3^d - 2)*Sum[(2^d - 1)^(wt[k] - 1), {k, 1, n/2 - 1}]]) / 4; a[0] = 0; a[1] = 1; Array[a, 50, 0]] (* Amiram Eldar, Aug 01 2023 *)

Formula

a(n) = 2 + (3/4)*(A160118(n) - 1) if n >= 2.

Extensions

Entry revised by Omar E. Pol and N. J. A. Sloane, Feb 16 2010
More terms from Nathaniel Johnston, Nov 13 2010
Corrected by Sean A. Irvine, Mar 23 2011, in response to correction to A160118
More terms from Amiram Eldar, Aug 01 2023

A194692 Corner sequence associated with A194440 and A194441.

Original entry on oeis.org

0, 2, 4, 8, 14, 22, 30, 42, 55, 67, 77, 93, 113, 145, 165, 189, 216, 236, 246, 262, 286, 322, 363, 411, 459, 513, 547, 591, 641, 721, 769, 817, 872, 908, 918, 934, 958, 994, 1035, 1083, 1137, 1205, 1267, 1347, 1427, 1551, 1646, 1750, 1839, 1933, 1977, 2025, 2093
Offset: 0

Views

Author

Omar E. Pol, Sep 01 2011

Keywords

Comments

The sequence gives the number of toothpicks and D-toothpicks after n-th stage in the D-toothpick "corner" structure related to the D-toothpick "wide" triangle (See A194440). The first differences (A194693) give the number of toothpicks or D-toothpicks added at n-th stage.

Crossrefs

A194694 Corner sequence associated with A194442 and A194443.

Original entry on oeis.org

0, 2, 4, 8, 14, 22, 30, 41, 57, 70, 80, 92, 112, 134, 160, 184, 220, 241, 251, 263
Offset: 0

Views

Author

Omar E. Pol, Sep 01 2011

Keywords

Comments

The sequence gives the number of toothpicks and D-toothpicks after n-th stage in the D-toothpick "corner" structure related to the D-toothpick "narrow" triangle (See A194442). The first differences (A194695) give the number of toothpicks or D-toothpicks added at n-th stage.

Crossrefs

A161210 Toothpick sequence starting at the outside corner of an infinite cube from which protrudes a half toothpick.

Original entry on oeis.org

0, 1, 3, 7, 14, 21, 28
Offset: 0

Views

Author

Omar E. Pol, Jun 06 2009

Keywords

Comments

The sequence gives the number of toothpicks after n rounds. A161211 (the first differences) gives the number added at the n-th round.
This structure is a three-dimensional version of the toothpick structure of A153006.
Toothpicks are placed following a rotation of axes: x,y,z,x,y,z,... and so on.
See A139250 and A160160 for more information about the toothpick sequences.

Crossrefs

A160416 Number of "ON" cells at n-th stage in simple 2-dimensional cellular automaton (see Comments for precise definition).

Original entry on oeis.org

0, 1, 8, 11, 32, 39, 80, 89, 146, 159
Offset: 0

Views

Author

Omar E. Pol, May 20 2009, Jun 14 2009

Keywords

Examples

			If we label the generations of cells turned ON by consecutive numbers we get the cell pattern shown below:
..9...9...9...9...9
...888.888.888.888.
...878.878.878.878.
...886668666866688.
..9..656.656.656..9
...886644464446688.
...878.434.434.878.
...886644222446688.
..9..656.212.656..9
000000000022446688.
0000000000.434.878.
000000000064446688.
000000000056.656..9
000000000066866688.
0000000000.878.878.
0000000000.888.888.
00000000009...9...9
0000000000.........
0000000000.........
		

Crossrefs

A161212 a(n) = A161210(n)*2.

Original entry on oeis.org

0, 2, 6, 14, 28, 42, 56
Offset: 0

Views

Author

Omar E. Pol, Jun 06 2009

Keywords

Crossrefs

A161214 a(n) = A161210(n)*3.

Original entry on oeis.org

0, 3, 9, 21, 42, 63, 84
Offset: 0

Views

Author

Omar E. Pol, Jun 06 2009

Keywords

Crossrefs

A161216 a(n) = A161210(n)*4.

Original entry on oeis.org

0, 4, 12, 28, 56, 84, 112
Offset: 0

Views

Author

Omar E. Pol, Jun 06 2009

Keywords

Crossrefs

A168112 Toothpick sequence starting with a straight line, with angle = Pi/4, from which protrudes a half toothpick.

Original entry on oeis.org

0, 1, 2, 4, 7, 10, 13, 19, 26, 32, 35, 41, 48, 56, 65, 81, 98, 108, 111, 117, 124, 132, 141, 157, 174, 186, 195, 211, 230, 252, 283, 329, 370, 388, 391, 397, 404, 412, 421, 437, 454, 466, 475, 491, 510, 532, 563, 609, 650, 670
Offset: 0

Views

Author

Omar E. Pol, Dec 07 2009

Keywords

Comments

On the infinite square grid, we start at round 0 drawing a straight line, with angle = Pi/4, from which protrudes a half toothpick.
At round 1 we place an orthogonal toothpick centered at the end.
In each subsequent round, for every exposed toothpick end, place an orthogonal toothpick centered at that end.
The sequence gives the number of toothpicks after n rounds.
See also A168113, the first differences.
For more information see A139250, which is the main entry for this sequence.

Crossrefs

Formula

a(n) = A160730(n)/2. [From Nathaniel Johnston, Mar 28 2011]

Extensions

Terms after a(34) from Nathaniel Johnston, Mar 28 2011

A152979 Records in A152978.

Original entry on oeis.org

1, 2, 3, 4, 7, 8, 9, 10, 15, 22, 23, 28, 35, 52, 64, 65, 74, 91, 122, 168, 176, 177, 186, 239, 304, 412, 512, 513, 524, 527, 599, 782, 1020, 1336, 1488, 1489, 1500, 1575, 1980, 2584, 3376, 4160, 4161, 4172, 4174, 4247, 4275, 4653, 5010, 6544, 8544
Offset: 1

Views

Author

Omar E. Pol, Dec 23 2008

Keywords

Comments

This sequence also gives the records in A152980. - Nathaniel Johnston, Apr 10 2011

Crossrefs

Extensions

a(16)-a(51) from Nathaniel Johnston, Apr 10 2011
Previous Showing 31-40 of 53 results. Next