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A140269 A number n is included if GCD((largest divisor of n that is <= sqrt(n)),(smallest divisor of n that is >=sqrt(n))) > 1. 1
4, 8, 9, 16, 18, 24, 25, 27, 32, 36, 48, 49, 50, 54, 60, 64, 75, 80, 81, 96, 98, 100, 108, 112, 120, 121, 125, 128, 135, 140, 144, 147, 150, 160, 162, 168, 169, 180, 189, 192, 196, 200, 216, 224, 225, 242, 243, 245, 250, 252, 256, 264, 270, 280, 288, 289, 294 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

EXAMPLE

The divisors of 48 are 1,2,3,4,6,8,12,16,24,48. The middle two of these divisors are 6 and 8, which are not coprime. So 48 is included in this sequence.

PROG

Contribution from Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Dec 20 2008: (Start)

(PARI) precdiv(n, k) = k=floor(k); while(k>0, if(n%k==0, return(k)); k--)

in140269(n) = local(d); d=precdiv(n, sqrt(n)); gcd(d, n\d)>1

for(n=1, 300, if(in140269(n), print1(n", "))) (End)

CROSSREFS

Cf. A033676, A033677, A140270.

Cf. A033676, A033677. [From Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Dec 20 2008]

Sequence in context: A034023 A086368 A034024 * A070003 A073539 A090779

Adjacent sequences:  A140266 A140267 A140268 * A140270 A140271 A140272

KEYWORD

nonn

AUTHOR

Leroy Quet May 16 2008

EXTENSIONS

More terms from Franklin T. Adams-Watters (FrankTAW(AT)Netscape.net), Dec 20 2008

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Last modified February 15 07:42 EST 2012. Contains 205717 sequences.