

A160430


The 3D toothpick sequence A160160, but using toothpicks of length 4; a(n) is the number of nodes occupied after n steps.


2



0, 5, 13, 29, 57, 85, 113, 145, 209, 329, 509, 613, 665, 697, 761, 881, 1073, 1273, 1505, 1817, 2377, 3217, 4309, 4761, 4921, 5009, 5097, 5233, 5425, 5625, 5857, 6169, 6729, 7569, 8697, 9425, 10017, 10641, 11601, 12873
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OFFSET

0,2


LINKS

Table of n, a(n) for n=0..39.
David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS


FORMULA

a(n) = A170884(n) + 2*A160160(n)


EXAMPLE

Each toothpick looks like this: ooooo.
The initial (zaxis) toothpick occupies 5 nodes. The next two, in the xdirection, add 8 further nodes, and so on.


CROSSREFS

Cf. A139250, A139251, A147562, A160118, A160120, A160160, A160170, A160379, A160420.
Sequence in context: A162329 A273026 A273077 * A023617 A023619 A020576
Adjacent sequences: A160427 A160428 A160429 * A160431 A160432 A160433


KEYWORD

nonn


AUTHOR

Omar E. Pol, May 13 2009


EXTENSIONS

Edited by N. J. A. Sloane, Jan 02 2010
Formula and more terms from Nathaniel Johnston, Nov 14 2010


STATUS

approved



