OFFSET
1,5
COMMENTS
Number of square totatives of n, i.e., number of perfect squares less than n that are coprime to n. - Michael De Vlieger, Dec 11 2017
LINKS
Reinhard Zumkeller, Table of n, a(n) for n = 1..10000
Eric Weisstein's World of Mathematics, Totative.
EXAMPLE
Only 2 squares, 1 and 9, are <= 14 and relatively prime to 14. So a(14) = 2.
MATHEMATICA
Table[Count[Range[Sqrt@ n]^2, _?(CoprimeQ[#, n] &)], {n, 104}]
PROG
(Haskell)
a057828 x = length $ filter ((== 1) . (gcd x)) $
takeWhile (<= x) $ tail a000290_list
-- Reinhard Zumkeller, Jul 22 2012
CROSSREFS
KEYWORD
nonn,look
AUTHOR
Leroy Quet, Nov 08 2000
STATUS
approved