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 1-3 of 3 results.

A151836 First differences of A147552.

Original entry on oeis.org

1, 4, 4, 12, 4, 12, 12, 28, 4, 12, 12, 28, 20, 28, 36, 68, 4, 12, 12, 28, 20, 28, 36, 68, 36, 28, 36, 68, 68, 76, 100, 172, 12, 28, 12, 28, 20, 28, 36, 68, 36, 28, 36, 68, 68, 76, 100, 172, 76, 28, 36, 68, 68, 76
Offset: 1

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Author

N. J. A. Sloane, Jul 13 2009

Keywords

Links

Crossrefs

Cf. A139250, A147552, A151837, A160721.

Extensions

Terms after a(30) from Nathaniel Johnston, Mar 27 2011

A151776 Number of ON states after n generations of cellular automaton based on f.c.c. lattice with each cell adjacent to its twelve neighbors.

Original entry on oeis.org

0, 1, 13, 25, 109, 121, 205, 385, 805, 817, 901, 1081, 1645, 2185, 2605, 3721, 5749, 5857, 5941, 6121, 6685, 7225, 7789, 9289, 12565, 14401, 14821, 15937, 18877, 23257, 25981, 32233, 42445, 43729, 44101, 44521
Offset: 0

Views

Author

N. J. A. Sloane, Jun 24 2009

Keywords

Comments

We take the f.c.c. lattice to consist of the points (X,Y,Z) of Z^3 with X+Y+Z even.
We start with a single ON cell at the origin.
A cell is turned ON if exactly one of its twelve neighbors is ON. An ON cell remains ON forever.
Analog of A147562, which is corresponding sequence for the square lattice Z^2.
If we just look at what happens in the (X,Y)-plane, we get A147552 and A151836.

Links

Crossrefs

Cf. A151777, A151778, A147562, A151725, A139250.

Extensions

Terms after a(30) from Nathaniel Johnston, Mar 27 2011

A299776 a(n) = 1 + 4*(A160120(n) - 1)/3.

Original entry on oeis.org

0, 1, 5, 9, 21, 25, 37, 49, 77, 89, 101, 113, 141, 161, 189, 225, 293, 329, 341, 353, 381, 401, 429, 465, 533, 577, 605, 641, 709, 777, 853, 945, 1101, 1209, 1237, 1249, 1277, 1297, 1325, 1361, 1429, 1473, 1501, 1537, 1605, 1673, 1749, 1841, 1997, 2113, 2157
Offset: 0

Views

Author

Omar E. Pol, Apr 03 2018

Keywords

Comments

Essentially this should be the 120-degree wedge of the cellular automaton of A160120 projected in four quadrants.
First differs from both A147552 and A160720 at a(9).

Links

Crossrefs

Cf. A139250, A147552, A160120. A160720.
Showing 1-3 of 3 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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