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 A065970 a(n) = n^2 * Sum_{primes p dividing n} (1 - 1/p^2). 1
 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 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Harry J. Smith, Table of n, a(n) for n = 1..1000 PROG (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 CROSSREFS Sequence in context: A007434 A128303 A123906 * A326890 A024463 A092954 Adjacent sequences: A065967 A065968 A065969 * A065971 A065972 A065973 KEYWORD nonn AUTHOR N. J. A. Sloane, Dec 09 2001 STATUS approved

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Last modified May 29 08:58 EDT 2023. Contains 363029 sequences. (Running on oeis4.)