A372447 - OEIS

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A372447

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

6

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

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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