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A320631
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Products of odd primes of nonprime squarefree index.
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5
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13, 29, 43, 47, 73, 79, 101, 113, 137, 139, 149, 163, 167, 169, 181, 199, 233, 257, 269, 271, 293, 313, 317, 347, 349, 373, 377, 389, 397, 421, 439, 443, 449, 467, 487, 491, 499, 557, 559, 571, 577, 601, 607, 611, 619, 631, 647, 653, 673, 677, 727, 733, 751
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OFFSET
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1,1
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LINKS
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EXAMPLE
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The sequence of terms begins:
13 = prime(6)
29 = prime(10)
43 = prime(14)
47 = prime(15)
73 = prime(21)
79 = prime(22)
101 = prime(26)
113 = prime(30)
137 = prime(33)
139 = prime(34)
149 = prime(35)
163 = prime(38)
167 = prime(39)
169 = prime(6)^2
181 = prime(42)
199 = prime(46)
233 = prime(51)
257 = prime(55)
269 = prime(57)
271 = prime(58)
293 = prime(62)
313 = prime(65)
317 = prime(66)
347 = prime(69)
349 = prime(70)
373 = prime(74)
377 = prime(6)*prime(10)
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MATHEMATICA
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Select[Range[1, 100, 2], With[{f=PrimePi/@First/@FactorInteger[#]}, And[And@@SquareFreeQ/@f, And@@Not/@PrimeQ/@f]]&]
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CROSSREFS
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Cf. A000040, A006450, A007821, A018252, A056239, A076610, A112798, A302242, A302478, A320628, A320629, A320630, A320633.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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