login
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.
6
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
OFFSET
1,3
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).
Sequence in context: A290569 A230698 A090234 * A275866 A007754 A144866
KEYWORD
nonn
AUTHOR
Antti Karttunen, May 08 2017
STATUS
approved