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A095990
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Numbers with ordered prime signature (1,2).
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10
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18, 50, 75, 98, 147, 242, 245, 338, 363, 507, 578, 605, 722, 845, 847, 867, 1058, 1083, 1183, 1445, 1587, 1682, 1805, 1859, 1922, 2023, 2523, 2527, 2645, 2738, 2883, 3179, 3362, 3698, 3703, 3757, 3971, 4107, 4205, 4418, 4693, 4805, 5043, 5547, 5618, 5819
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OFFSET
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1,1
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COMMENTS
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Numbers of the form p*q^2 where p and q are primes with p < q.
A054753 contains natural numbers with ordered prime signatures (2,1) and (1,2).
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LINKS
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EXAMPLE
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18 = 2*3*3, 50 = 2*5*5, 75 = 3*5*5, 98 = 2*7*7, 147 = 3*7*7, ...
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MATHEMATICA
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Take[ Sort[ Flatten[ Table[ Prime[p]*Prime[q]^2, {q, 2, 16}, {p, q - 1}]]], 46] (* Robert G. Wilson v, Jul 23 2004 *)
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PROG
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(PARI) list(lim)=my(v=List()); forprime(q=3, sqrtint(lim\2), forprime(p=2, min(lim\q^2, q-1), listput(v, p*q^2))); Set(v) \\ Charles R Greathouse IV, Feb 26 2014
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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