

A129381


a(1)=1. a(n) = the number of earlier terms which are coprime to floor(sqrt(n)).


1



1, 1, 2, 2, 2, 2, 2, 2, 8, 9, 9, 9, 9, 9, 9, 8, 8, 8, 8, 8, 8, 8, 8, 8, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 12, 48, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 49, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32, 32
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OFFSET

1,3


LINKS



EXAMPLE

Floor(sqrt(11)) = 3. So a(11) is the number of terms from among a(1),a(2),...a(10) which are coprime to 3. Terms a(1) through a(9) are each coprime to 3, so a(11) = 9.


MAPLE

a[1]:=1: for n from 2 to 100 do ct:=0: for j from 1 to n1 do if igcd(a[j], floor(sqrt(n)))=1 then ct:=ct+1 else fi od: a[n]:=ct: od: seq(a[n], n=1..100); # Emeric Deutsch, Apr 16 2007


CROSSREFS



KEYWORD

nonn


AUTHOR



EXTENSIONS



STATUS

approved



