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 31-40 of 49 results. Next

A194696 a(n) = 2*A194693(n).

Original entry on oeis.org

4, 4, 8, 12, 16, 16, 24, 26, 24, 20, 32, 40, 64, 40, 48, 54, 40, 20, 32, 48, 72, 82, 96, 96, 108, 68, 88, 100, 160, 96, 96, 110, 72, 20, 32, 48, 72, 82, 96, 108, 136, 124, 160, 160, 248, 190, 208, 178, 188, 88, 96, 136
Offset: 1

Views

Author

Omar E. Pol, Sep 03 2011

Keywords

Comments

Conjecture: number of toothpicks or D-toothpicks added to the structure of A194440 at stage 2^k+n, if k tends to infinity. It appears that rows of A194441 when written as a triangle converge to this sequence.

Examples

			Written as a triangle:
4,
4,
8,
12,16,
16,24,26,24,
20,32,40,64,40,48,54,40,
20,32,48,72,82,96,96,108,68,88,100,160,96,96,110,72,
20,32,48,72,82,96,108,136,124,160,160,248,190,208,178,...
		

Crossrefs

A194697 a(n) = 2*A194695(n).

Original entry on oeis.org

4, 4, 8, 12, 16, 16, 22, 32, 26, 20, 24, 40, 44, 52, 48, 72, 42, 20, 24
Offset: 1

Views

Author

Omar E. Pol, Sep 03 2011

Keywords

Comments

Conjecture: number of toothpicks or D-toothpicks added to the structure of A194442 at stage 2^k+n, if k tends to infinity. It appears that rows of A194443 when written as a triangle converge to this sequence.

Examples

			Written as a triangle:
4,
4,
8,
12,16,
16,22,32,26,
20,24,40,44,52,48,72,42,
20,24
		

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

A162349 First differences of A160412.

Original entry on oeis.org

3, 9, 9, 27, 9, 27, 27, 81, 9, 27, 27, 81, 27, 81, 81, 243, 9, 27, 27, 81, 27, 81, 81, 243, 27, 81, 81, 243, 81, 243, 243, 729, 9, 27, 27, 81, 27, 81, 81, 243, 27, 81, 81, 243, 81, 243, 243, 729, 27, 81, 81, 243, 81, 243, 243, 729, 81, 243, 243, 729, 243, 729
Offset: 1

Views

Author

Omar E. Pol, Jul 14 2009

Keywords

Comments

Note that if A048883 is written as a triangle then rows converge to this sequence. - Omar E. Pol, Nov 15 2009

Crossrefs

Programs

  • Mathematica
    a[n_] := 3^(1 + DigitCount[n - 1, 2, 1]); Array[a, 100] (* Amiram Eldar, Feb 02 2024 *)

Formula

a(n) = 3^A063787(n) = 3 * A048883(n-1). - Amiram Eldar, Feb 02 2024

Extensions

More terms from Omar E. Pol, Nov 15 2009
More terms from Colin Barker, Apr 19 2015
More terms from Amiram Eldar, Feb 02 2024

A168113 First differences of A168112.

Original entry on oeis.org

1, 1, 2, 3, 3, 3, 6, 7, 6, 3, 6, 7, 8, 9, 16, 17, 10, 3, 6, 7, 8, 9, 16, 17, 12, 9, 16, 19, 22, 31, 46, 41, 18, 3, 6, 7, 8, 9, 16, 17, 12, 9, 16, 19, 22, 31, 46, 41, 20, 9, 16, 19, 22, 31, 46, 43, 30, 31, 48
Offset: 1

Views

Author

Omar E. Pol, Dec 07 2009

Keywords

Comments

a(n) is the number of toothpicks added at the n-th round in the toothpick structure of A168112.

Examples

			If written as a triangle, begins:
1;
1;
2;
3,3;
3,6,7,6;
3,6,7,8,9,16,17,10;
3,6,7,8,9,16,17,12,9,16,19,22,31,46,41,18;
Rows converge to A168114.
		

Crossrefs

Formula

Observation: It appears that a(2^i+2) = 3, for i>0.
a(n) = A160731(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

A159793 a(n) = A153006(n)*2.

Original entry on oeis.org

0, 2, 6, 12, 18, 26, 40, 56, 66, 74, 88, 106, 126, 156, 200, 240, 258, 266, 280, 298, 318, 348, 392, 434, 462, 492, 538, 594, 664, 768, 896, 992, 1026, 1034, 1048, 1066, 1086, 1116, 1160, 1202, 1230, 1260, 1306, 1362, 1432, 1536, 1664, 1762, 1806, 1836, 1882, 1938
Offset: 0

Views

Author

Omar E. Pol, May 02 2009

Keywords

Crossrefs

Toothpick sequence: A139250.

Programs

  • PARI
    lista(nn) = concat(0, 2*Vec(x*((1+x)/(1-x))*prod(k=1, nn, 1+x^(2^k-1)+2*x^(2^k)) + O(x^nn))); \\ Jinyuan Wang, Mar 04 2020

Extensions

More terms from Jinyuan Wang, Mar 04 2020
Previous Showing 31-40 of 49 results. Next