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A081304 Number of numbers m <= n with prime factors less than 2*spf(m), where spf(m) is the smallest prime factor of m (A020639). 2
1, 2, 3, 4, 5, 6, 7, 8, 9, 9, 10, 11, 12, 12, 13, 14, 15, 16, 17, 17, 17, 17, 18, 19, 20, 20, 21, 21, 22, 22, 23, 24, 24, 24, 25, 26, 27, 27, 27, 27, 28, 28, 29, 29, 30, 30, 31, 32, 33, 33, 33, 33, 34, 35, 35, 35, 35, 35, 36, 36, 37, 37, 37, 38, 38, 38, 39, 39, 39, 39, 40, 41, 42 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n)+A081305(n)=n; a(114)=A081305(114)=57;

a(n)>=n/2 for n<=114, a(n)<n/2 for n>114.

LINKS

Table of n, a(n) for n=1..73.

CROSSREFS

Cf. A081306, A081303.

Sequence in context: A128635 A100637 A081063 * A137721 A245339 A324161

Adjacent sequences:  A081301 A081302 A081303 * A081305 A081306 A081307

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Mar 17 2003

STATUS

approved

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Last modified November 20 20:46 EST 2019. Contains 329347 sequences. (Running on oeis4.)