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 A059775 From solution to a counting problem. 0
 0, 24, 120, 360, 824, 1664, 2992, 5000, 7848, 11808, 17024, 23888, 32576, 43432, 56816, 73136, 92616, 115872, 143104, 174928, 211808, 254312, 302680, 357832, 420136, 490232, 568664, 656360, 753496, 861376, 980232, 1111016, 1254504 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 LINKS Emeric Deutsch, Murray S. Klamkin and Denis Constales, Solution to Problem 10540: Counting the Solutions, Amer. Math. Monthly, 108 (Feb. 2001), 172-173. MAPLE [seq(n*(n-1)*(n^2-n-1) + 4*add(floor(n/k^2)*phi(k), k=2..floor(sqrt(n))) - 2*add(floor(n/k)^2*phi(k), k=2..n), n=2..30)]; CROSSREFS Sequence in context: A114200 A229567 A069074 * A052762 A217056 A099317 Adjacent sequences:  A059772 A059773 A059774 * A059776 A059777 A059778 KEYWORD nonn AUTHOR N. J. A. Sloane, Feb 21 2001 STATUS approved

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Last modified December 15 09:05 EST 2019. Contains 329995 sequences. (Running on oeis4.)