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 A071147 Smallest squarefree number k with exactly n prime factors such that the sum the prime factors is divisible by the largest prime dividing k, or 0 if no such k exists. 8
 1, 2, 0, 30, 3135, 3570, 72930, 1231230, 14804790, 497668710, 14908423530, 278196808890, 12192694624110, 550939666387110, 21275256232500270, 1458502323630662310, 87988283090327810190, 3254611619240885033130, 261462818462495728868790, 9965666894849284108299810, 557940830126698960967415390, 90544636506979071680577724410 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS No solution exists for n=2, so a(2)=0. LINKS FORMULA A008472(k)/A006530(k) is integer; k is squarefree and has exactly n prime factors. EXAMPLE a(0) =       1 = 1; a(1) =       2 = 2; a(3) =      30 = 2 *  3 *  5; a(4) =    3135 = 3 *  5 * 11 * 19; a(5) =    3570 = 2 *  3 *  5 *  7 * 17; a(6) =   72930 = 2 *  3 *  5 * 11 * 13 * 17; a(7) = 1231230 = 2 *  3 *  5 *  7 * 11 * 13 * 41. CROSSREFS Cf. A008472, A006530, A000961, A025475, A037074, A071139-A071146. Sequence in context: A092177 A104466 A086487 * A156481 A176726 A156452 Adjacent sequences:  A071144 A071145 A071146 * A071148 A071149 A071150 KEYWORD nonn AUTHOR Labos Elemer, May 13 2002 EXTENSIONS Corrected and extended by Donovan Johnson, Apr 22 2008 Name corrected by Jon E. Schoenfield, Jul 08 2018 STATUS approved

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Last modified August 20 06:04 EDT 2019. Contains 326139 sequences. (Running on oeis4.)