The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A265381 Decimal representation of the middle column of the "Rule 158" elementary cellular automaton starting with a single ON (black) cell. 3
 1, 3, 7, 14, 29, 59, 119, 238, 477, 955, 1911, 3822, 7645, 15291, 30583, 61166, 122333, 244667, 489335, 978670, 1957341, 3914683, 7829367, 15658734, 31317469, 62634939, 125269879, 250539758, 501079517, 1002159035, 2004318071, 4008636142, 8017272285 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 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 Eric Weisstein's World of Mathematics, Elementary Cellular Automaton FORMULA Conjectures from Colin Barker, Dec 07 2015 and Apr 16 2019: (Start) a(n) = (-45+5*(-1)^n-(6-i*3)*(-i)^n-(6+3*i)*i^n+7*2^(4+n))/60 where i = sqrt(-1). a(n) = 2*a(n-1)+a(n-4)-2*a(n-5) for n>4. G.f.: (1+x+x^2) / ((1-x)*(1+x)*(1-2*x)*(1+x^2)). (End) EXAMPLE From Michael De Vlieger, Dec 09 2015: (Start) First 8 rows at left, ignoring "0" outside of range of 1's, the center column values in parentheses. The center column values up to that row are concatenated then converted into decimal at right:              Rule 158                   Binary     Decimal                 (1)                 ->         1 =   1               1 (1) 1               ->        11 =   3             1 1 (1) 0 1             ->       111 =   7           1 1 1 (0) 0 1 1           ->      1110 =  14         1 1 1 0 (1) 1 1 0 1         ->     11101 =  29       1 1 1 0 0 (1) 1 0 0 1 1       ->    111011 =  59     1 1 1 0 1 1 (1) 0 1 1 1 0 1     ->   1110111 = 119   1 1 1 0 0 1 1 (0) 0 1 1 0 0 1 1   ->  11101110 = 238 1 1 1 0 1 1 1 0 (1) 1 1 0 1 1 1 0 1 -> 111011101 = 477 (End) MATHEMATICA f[n_] := Block[{w = {}}, Do[AppendTo[w, Boole[Mod[k, 4] != 3]], {k, 0, n}]; FromDigits[w, 2]]; Table[f@ n, {n, 0, 32}] (* Michael De Vlieger, Dec 09 2015 *) CROSSREFS Cf. A071037. Sequence in context: A052997 A267210 A074988 * A066225 A305777 A139817 Adjacent sequences:  A265378 A265379 A265380 * A265382 A265383 A265384 KEYWORD nonn,easy AUTHOR Robert Price, Dec 07 2015 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 19 15:09 EDT 2020. Contains 337178 sequences. (Running on oeis4.)