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 A066859 Product of sums of divisors and non-divisors. 1
 0, 0, 8, 21, 54, 108, 160, 315, 416, 666, 648, 1400, 1078, 1944, 2304, 3255, 2430, 5148, 3400, 7056, 6368, 7812, 6048, 14400, 9114, 12978, 13520, 19600, 12150, 28296, 14848, 29295, 24624, 29214, 27936, 52325, 25270, 40860, 40544, 65700, 34398, 77472, 39688 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS A000203(n) + A024816(n) = A000217(n). LINKS David A. Corneth, Table of n, a(n) for n = 1..10000 FORMULA a(n) = A000203(n)*A024816(n). MAPLE a:= n-> (s-> s*(n*(n+1)/2-s))(numtheory[sigma](n)): seq(a(n), n=1..45); # Alois P. Heinz, Feb 05 2021 PROG (PARI) a(n) = my(s=sigma(n)); s*(n*(n+1)/2 - s); \\ Michel Marcus, Feb 05 2021 CROSSREFS Cf. A000203, A024816, A000217. Sequence in context: A344599 A138179 A067334 * A227653 A296198 A301538 Adjacent sequences: A066856 A066857 A066858 * A066860 A066861 A066862 KEYWORD nonn AUTHOR Reinhard Zumkeller, Jan 23 2002 STATUS approved

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Last modified June 5 19:44 EDT 2023. Contains 363138 sequences. (Running on oeis4.)