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A370395
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Numbers k that are neither squarefree nor prime powers sandwiched between twin primes.
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1
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12, 18, 60, 72, 108, 150, 180, 192, 198, 228, 240, 270, 312, 348, 420, 432, 522, 600, 660, 810, 828, 882, 1020, 1032, 1050, 1062, 1092, 1152, 1278, 1320, 1428, 1452, 1488, 1608, 1620, 1668, 1788, 1872, 1932, 1950, 1998, 2028, 2088, 2112, 2142, 2268, 2340, 2550
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OFFSET
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1,1
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COMMENTS
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This sequence contains 1062, 1278, 1608 while A258838 does not; A258838 includes 4, 6, 30, 42, 462, 570, etc.
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LINKS
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FORMULA
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EXAMPLE
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The number 12 is neither squarefree nor a prime power but comes between primes 11 and 13.
The number 30 is squarefree, though it comes between primes 29 and 31, it is not in the sequence.
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MATHEMATICA
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Select[1 + Select[Prime@ Range[100], PrimeQ[# + 2] &], Nor[SquareFreeQ[#], PrimePowerQ[#]] &]
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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