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A220145 The Collatz (3x+1) iteration mod 2 with bits combined. 3
1, 10, 10000101, 100, 100001, 100001010, 10000100010010101, 1000, 10000100010010101001, 1000010, 100001000100101, 1000010100, 1000010001, 100001000100101010, 100001000001010101, 10000, 1000010001001, 100001000100101010010, 100001000100101000101, 10000100 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This is essentially sequence A070165 mod 2 with bits in the same iteration combined. Note that A176999 is similar, but with a different encoding.

It appears that all numbers are distinct. Sequence A005186 tells how many numbers produce bit strings of a given length. Sequence A221468 converts to decimal and A221467 sorts them.

LINKS

T. D. Noe, Table of n, a(n) for n = 1..10000

EXAMPLE

For n = 7, the Collatz iteration is 7, 22, 11, 34, 17, 52, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1. Looking at these numbers in base 2 and reversing them, we obtain 10000100010010101.

MATHEMATICA

Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Table[FromDigits[Mod[Reverse[Collatz[n]], 2]], {n, 30}]

CROSSREFS

Cf. A005186, A070165, A176999, A221467, A221468.

Sequence in context: A013854 A210813 A116126 * A057141 A034249 A131679

Adjacent sequences:  A220142 A220143 A220144 * A220146 A220147 A220148

KEYWORD

nonn,base

AUTHOR

T. D. Noe, Jan 17 2013

STATUS

approved

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Last modified August 22 16:37 EDT 2019. Contains 326179 sequences. (Running on oeis4.)