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A089576 Let p_k = k-th prime, let f((p_k)^n) = m where m is the largest power of p_(k+1) < (p_k)^n. a(n) = number of iterations of f to reach 1, starting from n and starting from k = 1. 0
0, 1, 2, 2, 3, 4, 4, 4, 5, 5, 6, 6, 6, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 9, 10, 10, 10, 11, 11, 11, 11, 11, 12, 12, 12, 13, 13, 13, 13, 14, 15, 15, 15, 15, 15, 15, 15, 15, 15, 15, 16, 16, 16, 17, 18, 18, 18, 18, 18, 18, 18, 18, 19, 19, 19, 19, 19 (list; graph; refs; listen; history; internal format)
OFFSET

0,3

EXAMPLE

a(5)=4 as f(2^5)=3^3 < 2^5, f(3^3)=5^2 < 3^3, f(5^2)=7 < 5^2 and f(7)=11^0 < 7.

CROSSREFS

Sequence in context: A189638 A097535 A060018 * A076642 A135304 A112325

Adjacent sequences:  A089573 A089574 A089575 * A089577 A089578 A089579

KEYWORD

easy,nonn

AUTHOR

Naohiro Nomoto (pcmusume(AT)m11.alpha-net.ne.jp), Dec 29 2003

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Last modified February 15 21:56 EST 2012. Contains 205860 sequences.