login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A222600 Least number k such that the difference between the number of halving and tripling steps in the Collatz (3x+1) iteration is n. 1
1, 2, 4, 3, 6, 12, 7, 9, 18, 25, 33, 43, 39, 78, 105, 135, 123, 169, 159, 295, 283, 111, 222, 297, 175, 103, 91, 121, 31, 27, 54, 73, 97, 129, 171, 231, 313, 411, 543, 327, 649, 859, 763, 1017, 1351, 1215, 703, 937, 871, 1161, 2223, 3097, 2631, 3567, 3175, 4233 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

COMMENTS

This is the first number in row n of A222599.

LINKS

T. D. Noe, Table of n, a(n) for n = 0..264 (searching until the Collatz sequence has a term greater than 2^63)

MATHEMATICA

Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; nn = 50; t = Table[0, {nn}]; n = 0; While[Min[t] == 0, n++; c = Collatz[n]; e = Select[c, EvenQ]; diff = 2*Length[e] - Length[c]; If[diff < nn - 1 && t[[diff + 2]] == 0, t[[diff + 2]] = n]]; t

CROSSREFS

Cf. A213678, A222599.

Sequence in context: A258046 A225055 A120947 * A046793 A182940 A101278

Adjacent sequences:  A222597 A222598 A222599 * A222601 A222602 A222603

KEYWORD

nonn

AUTHOR

T. D. Noe, Mar 04 2013

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 15 13:47 EST 2019. Contains 329149 sequences. (Running on oeis4.)