OFFSET
0,2
COMMENTS
A001025 is a subsequence. - Altug Alkan, Dec 23 2015
Rules 38, 134 and 166 also generate this sequence.
REFERENCES
S. Wolfram, A New Kind of Science, Wolfram Media, 2002; p. 55.
LINKS
Robert Price, Table of n, a(n) for n = 0..999
Hans Montanus and Ron Westdijk, Cellular Automation and Binomials, Green Blue Mathematics (2022), p. 22.
Eric Weisstein's World of Mathematics, Elementary Cellular Automaton
Index entries for linear recurrences with constant coefficients, signature (0,16).
FORMULA
From Colin Barker, Dec 23 2015 and Apr 13 2019: (Start)
a(n) = 4^(n-1)*(5-(-1)^n).
a(n) = 16*a(n-2) for n>1.
G.f.: (1+6*x) / ((1-4*x)*(1+4*x)).
(End)
MATHEMATICA
rule=6; rows=20; ca=CellularAutomaton[rule, {{1}, 0}, rows-1, {All, All}]; (* Start with single black cell *) catri=Table[Take[ca[[k]], {rows-k+1, rows+k-1}], {k, 1, rows}]; (* Truncated list of each row *) Table[FromDigits[catri[[k]], 2], {k, 1, rows}] (* Decimal Representation of Rows *)
LinearRecurrence[{0, 16}, {1, 6}, 30] (* Harvey P. Dale, May 25 2016 *)
PROG
(Python) print([int(4**(n-1)*(5-(-1)**n)) for n in range(30)]) # Karl V. Keller, Jr., Jun 03 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Robert Price, Dec 22 2015
STATUS
approved