

A213258


Positive integers that are not in A213257.


8



4, 12, 20, 28, 32, 36, 44, 52, 60, 68, 76, 84, 92, 96, 100, 108, 116, 124, 132, 140, 148, 156, 160, 164, 172, 180, 188, 196, 204, 212, 220, 224, 228, 236, 244, 252, 256, 260, 268, 276, 284, 288, 292, 300, 308, 316, 324, 332, 340, 348, 352, 356, 364, 372, 380, 388, 396, 404, 412, 416, 420, 428, 436, 444, 452, 460, 468, 476, 480, 484, 492, 500
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OFFSET

1,1


COMMENTS

Conjecture. The terms of this sequence are given by the positions of 2 in the fixedpoint of the morphism 0 > 01, 1 > 02, 2 > 03, 3 > 01 (see A191255). (This has been confirmed for over 5000 terms of A213257.) To illustrate, the fixedpoint of the indicated morphism is {0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,1,0,1,0,2,0,...} and 2 occurs at positions {4,12,20,...}, integers in this sequence but missing from A213257.
It appears that the terms of this sequence are all of the form of 4 times an odd integer multiplied by a nonnegative power of 8.
The above two conjectures are correct. This is indeed positions of 2 in A191255, and numbers of the form 2^(3t+2)*s where s is an odd number.  Jianing Song, Sep 21 2018


LINKS

Table of n, a(n) for n=1..72.


CROSSREFS

Cf. A191255, A213257.
Sequence in context: A030387 A269931 A043437 * A141065 A190748 A273253
Adjacent sequences: A213255 A213256 A213257 * A213259 A213260 A213261


KEYWORD

nonn


AUTHOR

John W. Layman, Jun 07 2012


STATUS

approved



