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Search: id:A096156
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| A096156 |
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Numbers with prime signature (2,1). |
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+0
4
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| 12, 20, 28, 44, 45, 52, 63, 68, 76, 92, 99, 116, 117, 124, 148, 153, 164, 171, 172, 175, 188, 207, 212, 236, 244, 261, 268, 275, 279, 284, 292, 316, 325, 332, 333, 356, 369, 387, 388, 404, 412, 423, 425, 428, 436, 452, 475, 477, 508, 524, 531, 539, 548, 549
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Numbers of the form p^2 * q where p and q are primes with p < q.
Also a(n) = the members of A054753 which are not in A095990.
There are pairs which differ by 1, which is not the case in A095990, beginning with 44 and 45, 116 and 117, 171 and 172, 332 and 333, etc.
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EXAMPLE
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a(2) = 20 because 20 = 2*2*5 and 2 < 5.
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MATHEMATICA
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Take[ Sort[ Flatten[ Table[ Prime[p]^2 Prime[q], {q, 2, 33}, {p, q - 1}]]], 54] (from Robert G. Wilson v Jul 28 2004)
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CROSSREFS
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Cf. A095990.
Sequence in context: A090767 A117227 A110187 this_sequence A107277 A124672 A109547
Adjacent sequences: A096153 A096154 A096155 this_sequence A096157 A096158 A096159
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KEYWORD
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nonn,easy
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AUTHOR
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Alford Arnold (alford1940(AT)aol.com), Jul 24 2004
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EXTENSIONS
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Edited and extended by Robert G. Wilson v (rgwv(AT)rgwv.com) and Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jul 27 2004
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