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A038184 One-dimensional cellular automaton 'sigma' (Rule 150): 000,001,010,011,100,101,110,111 -> 0,1,1,0,1,0,0,1. 9
1, 7, 21, 107, 273, 1911, 5189, 28123, 65793, 460551, 1381653, 7039851, 17829905, 124809335, 340873541, 1840690907, 4295032833, 30065229831, 90195689493, 459568513131, 1172543963409, 8207807743863, 22286925370437 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

Generation n (starting from the generation 0: 1) interpreted as a binary number.

Rows of the mod 2 trinomial triangle (A027907), interpreted as binary numbers: 1, 111, 10101, 1101011, ... - Jacob A. Siehler, Aug 25 2006

LINKS

Table of n, a(n) for n=0..22.

Index entries for sequences related to cellular automata

Eric Weisstein's World of Mathematics, Rule 150

MAPLE

bit_n := (x, n) -> `mod`(floor(x/(2^n)), 2);

sigmagen := proc(n) option remember: if (0 = n) then (1)

else sum('((bit_n(sigmagen(n-1), i)+bit_n(sigmagen(n-1), i-1)+bit_n(sigmagen(n-1), i-2)) mod 2)*(2^i)', 'i'=0..(2*n)) fi: end:

MATHEMATICA

f[n_] := Sum[2^k*Coefficient[ #, x, k], {k, 0, 2n}] & @ Expand[(1 + x + x^2)^n, Modulus -> 2] - Jacob A. Siehler, Aug 25 2006

CROSSREFS

Cf. A006977, A006978, A038183, A038185 (other cellular automata). Cf. A048710, A048720.

Cf. A027907, A001317.

Sequence in context: A100025 A121157 A219152 * A001185 A001693 A061961

Adjacent sequences:  A038181 A038182 A038183 * A038185 A038186 A038187

KEYWORD

nonn

AUTHOR

Antti Karttunen, Feb 15 1999

STATUS

approved

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Last modified April 17 12:15 EDT 2014. Contains 240635 sequences.