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A286380 a(n) = the minimum number of iterations of the reduced Collatz function R required to yield 1. The function R (A139391) is defined as R(k) = (3k+1)/2^r, with r as large as possible. 2
0, 1, 2, 1, 1, 3, 5, 1, 6, 2, 4, 3, 2, 6, 5, 1, 3, 7, 6, 2, 1, 5, 4, 3, 7, 3, 41, 6, 5, 6, 39, 1, 8, 4, 3, 7, 6, 7, 11, 2, 40, 2, 9, 5, 4, 5, 38, 3, 7, 8, 7, 3, 2, 42, 41, 6, 10, 6, 10, 6, 5, 40, 39, 1, 8, 9, 8, 4, 3, 4, 37, 7, 42, 7, 3, 7, 6, 12, 11, 2, 6, 41, 40, 2, 1, 10, 9, 5, 9, 5, 33, 5, 4, 39, 38, 3, 43, 8, 7, 8, 7, 8, 31, 3, 12, 3, 36, 42, 41, 42, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Index entries for sequences related to 3x+1 (or Collatz) problem

FORMULA

a(1) = 0; for n > 1, a(n) = 1 + a(A139391(n)).

Other identities. For all n >= 1:

a(n) + A000035(n) = A078719(n).

PROG

(Scheme) (define (A286380 n) (if (= 1 n) 0 (+ 1 (A286380 (A139391 n)))))

CROSSREFS

Cf. A075680 (the odd bisection).

Cf. A078719, A139391.

Sequence in context: A290569 A230698 A090234 * A275866 A007754 A144866

Adjacent sequences:  A286377 A286378 A286379 * A286381 A286382 A286383

KEYWORD

nonn

AUTHOR

Antti Karttunen, May 08 2017

STATUS

approved

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Last modified October 14 14:45 EDT 2019. Contains 328019 sequences. (Running on oeis4.)