

A255366


Total number of ON cells at stage n of twodimensional cellular automaton defined by the rules of the "UlamWarburton" twodimensional cellular automaton (A147562) for two of its wedges and defined by "Rule 750" using the von Neumann neighborhood (A169707) for the two other wedges.


7



1, 5, 9, 21, 25, 37, 53, 85, 89, 101, 117, 149, 165, 205, 257, 341, 345, 357, 373, 405, 421, 461, 513, 597, 613, 653, 705, 797, 857, 989, 1141, 1365, 1369, 1381, 1397, 1429, 1445, 1485, 1537, 1621, 1637, 1677, 1729, 1821, 1881, 2013, 2165, 2389, 2405, 2445, 2497
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OFFSET

1,2


COMMENTS

First differs from A162795 at a(14), but it appears that then they share infinitely many terms. It appears that this is very close to A162795 rather than both A147562 and A169707.
The graphs of both A162795 and this sequence are intertwined.
Note that there are four main versions of this cellular automaton, depending on whether the wedges with the same rule are opposite or perpendicular and also depending on whether each mentioned version is represented by the "onestep rook" illustration or by the "onestep bishop" illustration. The four versions are represented by this sequence.
a(43) = 1729 is also the HardyRamanujan number.


LINKS

Table of n, a(n) for n=1..51.
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
Index entries for sequences related to cellular automata


FORMULA

a(n) = (A147562(n) + A169707(n))/2.
It appears that a(n) = A147562(n) = A162795(n) = A169709(n), if n is a member of A048645, or in other words: if the binary weight of n is 1 or 2, but note that a(n) = A162795(n) for many other values of n.


EXAMPLE

a(43) = (1705 + 1753)/2 = 3458/2 = 1729.


CROSSREFS

Cf. A001235, A048645, A139250, A147562, A160164, A162795, A169707.
Sequence in context: A147552 A147562 A162795 * A269522 A169707 A256260
Adjacent sequences: A255363 A255364 A255365 * A255367 A255368 A255369


KEYWORD

nonn,look


AUTHOR

Omar E. Pol, Feb 21 2015


STATUS

approved



