cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A182028 Take first n bits of the infinite Fibonacci word A003849, regard them as a binary number, then convert it to base 10.

Original entry on oeis.org

0, 1, 2, 4, 9, 18, 37, 74, 148, 297, 594, 1188, 2377, 4754, 9509, 19018, 38036, 76073, 152146, 304293, 608586, 1217172, 2434345, 4868690, 9737380, 19474761, 38949522, 77899045, 155798090, 311596180, 623192361, 1246384722, 2492769444, 4985538889, 9971077778
Offset: 0

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Author

Reinhard Zumkeller, Apr 07 2012

Keywords

Comments

a(n) mod 2 = A003849(n);
a(n) = A000225(n+1) - A044432(n).

Examples

			0 ->                            0 -> a(0) = 0,
0,1 ->                         01 -> a(1) = 1,
0,1,0 ->                      010 -> a(2) = 2,
0,1,0,0 ->                   0100 -> a(3) = 4,
0,1,0,0,1 ->                01001 -> a(4) = 9,
0,1,0,0,1,0 ->             010010 -> a(5) = 18,
0,1,0,0,1,0,1 ->          0100101 -> a(6) = 37
0,1,0,0,1,0,1,0 ->       01001010 -> a(7) = 74
0,1,0,0,1,0,1,0,0 ->    010010100 -> a(8) = 148,
0,1,0,0,1,0,1,0,0,1 -> 0100101001 -> a(9) = 297.
		

Crossrefs

Programs

  • Haskell
    a182028 n = a182028_list !! n
    a182028_list = scanl1 (\v b -> 2 * v + b) a003849_list
  • Mathematica
    nesting = 7; A003849 = Flatten[Nest[{#, #[[1]]}&, {0, 1}, nesting]]; a[n_] := FromDigits[Take[A003849, n+1], 2]; Table[a[n], {n, 0, Length[A003849] - 1}] (* Jean-François Alcover, Feb 13 2016 *)

Formula

a(n) = 2*a(n-1) + A003849(n) for n > 0, a(0) = 0.