

A365742


Length of the largest subset of 1,...,n on which the Euler totient function phi A000010 is constant.


3



1, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 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, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10
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OFFSET

1,2


LINKS



FORMULA

Pollack et al. showed that A365737(n)a(n) > n^0.18 for large n.


PROG

(Python)
from collections import Counter
from sympy import totient
def A365742(n): return max(Counter(totient(i) for i in range(1, n+1)).values())


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



