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A175021 A positive integer n is included if n is not the smallest positive integer with its particular multiset of run-lengths (of either 0 or 1 considered together) in its binary representation. 2
6, 11, 13, 14, 20, 22, 23, 25, 26, 27, 28, 29, 30, 38, 39, 40, 41, 43, 44, 45, 46, 47, 49, 50, 52, 53, 54, 55, 57, 58, 59, 60, 61, 62, 70, 72, 75, 77, 78, 79, 80, 81, 82, 83, 84, 86, 87, 88, 89, 90, 91, 92, 93, 94, 95, 97, 98, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A175020 contains those positive integers not in this sequence.

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..10000

EXAMPLE

9 in binary is 1001. The run lengths form the multiset (1,2,1). Since no positive integer < 9 has this same multiset of run lengths, then 9 is not in this sequence. On the other hand, 23 in binary is 10111. The run-lengths are (1,1,3). But 17 (which is < 23) in binary is 10001, which has the run-lengths of (1,3,1). Since the multisets (1,1,3) and (1,3,1) are identical, then 23 is in this sequence.

MATHEMATICA

Block[{nn = 109, s}, s = Array[Sort@ Map[Length, Split@ IntegerDigits[#, 2]] &, nn]; Complement[Range[nn], Values[PositionIndex@ s][[All, 1]] ]] (* Michael De Vlieger, Sep 03 2017 *)

CROSSREFS

Cf. A175020.

Sequence in context: A219553 A015870 A004471 * A315367 A046953 A121765

Adjacent sequences: A175018 A175019 A175020 * A175022 A175023 A175024

KEYWORD

base,nonn

AUTHOR

Leroy Quet, Nov 03 2009

EXTENSIONS

Extended by Ray Chandler, Mar 11 2010

STATUS

approved

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Last modified December 2 23:09 EST 2022. Contains 358510 sequences. (Running on oeis4.)