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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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..77.

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 n-1 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

Cf. A129382.

Sequence in context: A299150 A202448 A339165 * A319991 A323275 A139514

Adjacent sequences:  A129378 A129379 A129380 * A129382 A129383 A129384

KEYWORD

nonn

AUTHOR

Leroy Quet, Apr 12 2007

EXTENSIONS

More terms from Emeric Deutsch, Apr 16 2007

STATUS

approved

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Last modified January 18 11:57 EST 2022. Contains 350455 sequences. (Running on oeis4.)