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A065970
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a(n) = n^2 * Sum_{primes p dividing n} (1 - 1/p^2).
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1
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0, 3, 8, 12, 24, 59, 48, 48, 72, 171, 120, 236, 168, 339, 416, 192, 288, 531, 360, 684, 824, 843, 528, 944, 600, 1179, 648, 1356, 840, 2339, 960, 768, 2048, 2019, 2376, 2124, 1368, 2523, 2864, 2736, 1680, 4619, 1848, 3372, 3744, 3699, 2208
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OFFSET
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1,2
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LINKS
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PROG
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(PARI) { for (n=1, 1000, s=0; p=2; while (p<=n, if(n%p == 0, s+=1 - 1/p^2); p=nextprime(p + 1)); write("b065970.txt", n, " ", n^2*s) ) } \\ Harry J. Smith, Nov 05 2009
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CROSSREFS
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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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