A317543 Positions of 1's in A317542, the formal inverse of the period-doubling sequence A096268.

1, 5, 7, 13, 17, 23, 29, 31, 37, 49, 55, 61, 65, 71, 77, 95, 101, 113, 119, 125, 127, 133, 145, 151, 157, 193, 199, 205, 223, 229, 241, 247, 253, 257, 263, 269, 287, 293, 305, 311, 317, 383, 389, 401, 407, 413, 449, 455, 461, 479, 485, 497, 503, 509, 511, 517, 529

Offset

0,2

Links

Table of n, a(n) for n=0..56.

N. Rampersad and M. Stipulanti, The Formal Inverse of the Period-Doubling Sequence, arXiv preprint arXiv:1807.11899 [math.CO], 2018.

Mathematica

a[0] = 1;
a[n_] :=
 Module[{m, u, i},
  u[0] = 0; u[1] = 1; u[2] = 0; u[3] = 0;
  u[i_] := If[EvenQ[i], 0, If[IntegerQ[(i - 1)/4], u[2 ((i - 1)/4) - 1], u[(i - 3)/4]]];
  m = a[n - 1] + 1;
  While[u[m] == 0, m++];
  m
  ]

Crossrefs

Cf. A096268, A317542, A317544.

Sequence in context: A216771 A216690 A095283 * A253297 A163385 A368277

Adjacent sequences: A317540 A317541 A317542 * A317544 A317545 A317546

Keyword

nonn

Author

Manon Stipulanti, Jul 30 2018

Status

approved