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A129139 a(n) = number of positive integers which are coprime to n and are <= d(n), where d(n) = A000005(n). 1
1, 1, 2, 2, 2, 1, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 2, 2, 2, 2, 3, 2, 2, 3, 3, 2, 3, 3, 2, 2, 2, 3, 3, 2, 4, 3, 2, 2, 3, 3, 2, 2, 2, 3, 3, 2, 2, 3, 3, 2, 3, 3, 2, 3, 4, 3, 3, 2, 2, 3, 2, 2, 4, 4, 4, 3, 2, 3, 3, 2, 2, 4, 2, 2, 3, 3, 4, 3, 2, 4, 4, 2, 2, 3, 4, 2, 3, 4, 2, 3, 4, 3, 3, 2, 4, 4, 2, 3, 4, 4, 2, 3, 2, 4, 4 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,3

LINKS

Table of n, a(n) for n=1..105.

EXAMPLE

d(16) = 5. So a(16) is the number of integers coprime to 16 which are <= 5. There are 3 such integers: 1, 3, 5; so a(16) = 3.

MAPLE

with(numtheory): a:=proc(n) local ct, j: ct:=0: for j from 1 to tau(n) do if gcd(j, n)=1 then ct:=ct+1 else fi od: ct; end: seq(a(n), n=1..140); # Emeric Deutsch, Apr 02 2007

CROSSREFS

Cf. A129138, A126131, A074919.

Sequence in context: A251139 A195061 A064130 * A032539 A122922 A278570

Adjacent sequences:  A129136 A129137 A129138 * A129140 A129141 A129142

KEYWORD

nonn

AUTHOR

Leroy Quet, Mar 30 2007

EXTENSIONS

More terms from Emeric Deutsch, Apr 02 2007

STATUS

approved

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Last modified September 27 22:36 EDT 2020. Contains 337388 sequences. (Running on oeis4.)