A372447 a(n) = A000523(A372443(n)); One less than the binary length of the n-th iterate of 27 with Reduced Collatz-function R.

4, 5, 4, 5, 6, 6, 7, 6, 6, 7, 6, 7, 7, 7, 8, 8, 9, 8, 7, 7, 8, 8, 8, 8, 8, 9, 10, 10, 11, 9, 10, 11, 11, 9, 8, 8, 5, 4, 5, 5, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

0,1

Links

Table of n, a(n) for n=0..72.

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

Prog

(PARI)
A000265(n) = (n>>valuation(n, 2));
A000523(n) = logint(n, 2);
A372443(n) = { my(x=27); while(n, x=A000265(3*x+1); n--); (x); };
A372447(n) = A000523(A372443(n));

Crossrefs

Cf. A000523, A372443.

Sequence in context: A245078 A276868 A182495 * A265300 A223170 A303275

Adjacent sequences: A372444 A372445 A372446 * A372448 A372449 A372450

Keyword

nonn

Author

Antti Karttunen, May 03 2024

Status

approved