A151922 Number of first-quadrant cells (including the two boundaries) that are "ON" after n-th stage of the Holladay-Ulam cellular automaton.

1, 3, 5, 9, 11, 15, 19, 29, 31, 35, 39, 49, 53, 63, 73, 101, 103, 107, 111, 121, 125, 135, 145, 173, 177, 187, 197, 225, 235, 263, 291, 373, 375, 379, 383, 393, 397, 407, 417, 445, 449, 459, 469, 497, 507, 535, 563, 645

Offset

0,2

Comments

See A079314, the first differences and A147562, the main entry for this CA, for further information.

Links

Paolo Xausa, Table of n, a(n) for n = 0..10000

David Applegate, Omar E. Pol and N. J. A. Sloane, The Toothpick Sequence and Other Sequences from Cellular Automata, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.]

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) = A079316(2n).

Mathematica

A151922list[nmax_]:=Accumulate[Join[{1}, 3^(DigitCount[Range[nmax], 2, 1]-1)+1]]; A151922list[100] (* Paolo Xausa, Jun 29 2023 *)

Crossrefs

Cf. A079314, A079316, A139250, A147562, A160406.

Sequence in context: A002731 A006046 A161830 * A233762 A104635 A210537

Adjacent sequences: A151919 A151920 A151921 * A151923 A151924 A151925

Keyword

nonn,easy

Author

N. J. A. Sloane, Aug 05 2009

Extensions

Extended (a(30)-a(47)) and edited by Omar E. Pol, Nov 21 2010

Status

approved