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A175125 a(n) = number of natural number m such that number of steps of iterations of {r - (largest divisor d < r)} needed to reach 1 starting at r = m is equal to n. 4
1, 1, 2, 3, 5, 9, 13, 23 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

See A105017, A000079, A064097.

LINKS

Table of n, a(n) for n=0..7.

EXAMPLE

Example (a(4)=5): There are five numbers (7,9,10,12,16) with 4 steps of defined iteration: 7-1=6, 6-3=3, 3-1=2, 2-1=1; 9-3=6, 6-3=3, 3-1=2, 2-1=1; 10-5=5, 5-1=4, 4-2=2, 2-1=1; 12-6=6, 6-3=3, 3-1=2, 2-1=1; 16-8=8, 8-4=4, 4-2=2, 2-1=1.

CROSSREFS

Sequence in context: A060482 A018138 A228129 * A171925 A186946 A057225

Adjacent sequences:  A175122 A175123 A175124 * A175126 A175127 A175128

KEYWORD

nonn

AUTHOR

Jaroslav Krizek, Feb 15 2010

STATUS

approved

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Last modified June 25 00:41 EDT 2017. Contains 288708 sequences.