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A078767
Let f(n) = A003434(n) be the number of iterations of phi needed to reach 1. Then a(n) = max(f(1), f(2), ..., f(n)).
0
0, 1, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 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, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 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, 7, 7, 7, 7, 7
OFFSET
1,3
PROG
(PARI) epr(m, c)=if (c>0, m=eulerphi(m); c--; epr(m, c), m) x=1; for (n=1, 100, while (epr(n, x)>1, x++); print1(x", "))
CROSSREFS
Cf. A003434.
Sequence in context: A236857 A156874 A294234 * A331137 A093125 A226390
KEYWORD
easy,nonn
AUTHOR
Jon Perry, Jan 09 2003
EXTENSIONS
Description corrected by Mark Hudson (mrmarkhudson(AT)hotmail.com), Jan 31 2003
STATUS
approved