

A090532


Let f(n) = n  pi(n). Then a(n) = least number of steps such that f(f(...(n)))=1.


1



1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9, 9
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OFFSET

2,3


LINKS

Table of n, a(n) for n=2..106.


EXAMPLE

a(10) = 3, 10 >6 >3 >1.
a(100) = 9.
f(100) =10025 = 75, f(75) = 7521= 54, f(54) = 5416 = 38, f(38) = 3812= 26, f(26) = 269 = 17, f(17) = 177 = 10, f(10) = 104 =6, f(6) = 63=3, f(3) = 32 =1.


CROSSREFS

Cf. A025003.
Sequence in context: A023967 A278163 A260999 * A003058 A000194 A168255
Adjacent sequences: A090529 A090530 A090531 * A090533 A090534 A090535


KEYWORD

nonn


AUTHOR

Amarnath Murthy, Dec 07 2003


EXTENSIONS

Corrected and extended by Sam Handler (sam_5_5_5_0(AT)yahoo.com), Dec 11 2004


STATUS

approved



