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A186170
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Number of prime factors times n minus sum of divisors.
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1
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-1, -1, -1, 1, -1, 0, -1, 9, 5, 2, -1, 8, -1, 4, 6, 33, -1, 15, -1, 18, 10, 8, -1, 36, 19, 10, 41, 28, -1, 18, -1, 97, 18, 14, 22, 53, -1, 16, 22, 70, -1, 30, -1, 48, 57, 20, -1, 116, 41, 57, 30, 58, -1, 96, 38, 104, 34, 26, -1, 72, -1, 28, 85, 257, 46, 54, -1
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OFFSET
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1,8
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COMMENTS
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Places n where a(n) is prime are: 9, 10, 25, 27, 32, 36, 49, 64,...
Places n where a(n^2) is prime are: 3, 5, 6, 7, 8,...
Number of prime factors counted with multiplicity. - Harvey P. Dale, Jan 23 2019
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LINKS
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EXAMPLE
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a(8) = (number of prime factors)*8 - (sum of divisors) = 3*8 - (1+2+4+8) = 24 - 15 = 9.
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MAPLE
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n*numtheory[bigomega](n)-numtheory[sigma](n) ;
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MATHEMATICA
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Table[PrimeOmega[n]n-DivisorSigma[1, n], {n, 70}] (* Harvey P. Dale, Jan 23 2019 *)
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PROG
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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STATUS
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approved
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