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 A300393 Least squarefree number with n prime factors whose average is an integer. 1
 2, 15, 42, 1365, 2730, 451605, 870870, 140645505, 300690390, 139098404445, 304075581810, 217908972526245, 485155825624470, 378943703223140055, 1033538145201932370, 1433000638322479231005, 1987938667108592728530, 4573285492841794762027995, 12549856805456545895209890 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS A103622 lists the average values. The parity of a(n) is different from the parity of n. - David A. Corneth, Mar 20 2018 LINKS Paolo P. Lava, Table of n, a(n) for n = 1..30 FORMULA a(1) = 2; 2/1 = 2; a(2) = 15; (3+5)/2 = 4; a(3) = 42; (2+3+7)/3 = 4; a(4) = 1365; (3+5+7+13)/4 = 7; a(5) = 2730; (2+3+5+7+13)/5 = 6. MAPLE with(combinat): P:=proc(q) local a, b, c, d, j, k, x; x:=[]; for j from 1 to q do x:=[op(x), ithprime(j)]; od; for j from 1 to q do a:=choose(x, j); b:=10^40; d:=0; for k from 1 to nops(a) do c:=convert(a[k], `+`)/j; if frac(c)=0 and c

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Last modified February 16 12:48 EST 2019. Contains 320163 sequences. (Running on oeis4.)