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 A136742 Product of the n-th run of squarefree numbers. 6
 6, 210, 110, 2730, 17, 19, 10626, 26, 26970, 39270, 54834, 74046, 2162, 51, 53, 55, 195054, 3782, 287430, 342930, 5402, 474474, 6806, 635970, 89, 91, 830490, 97, 1061106, 1190910, 1330890, 1481430, 14042, 15006, 127, 2196870, 17822, 2627934 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS All terms are squarefree; a(n) mod A072284(n) = 0; A136743(n) = A001221(a(n)). LINKS Robert Israel, Table of n, a(n) for n = 1..10000 Eric Weisstein's World of Mathematics, Squarefree FORMULA a(n) = Product_{k=0..A120992(n)-1} (A072284(n)+k). EXAMPLE n=10: A072284(10)=33, A120992(10)=3: a(10)=33*34*35=39270. MAPLE R:= NULL: state:= false: count:= 0: for n from 1 while count < 100 do if numtheory:-issqrfree(n) then if state then P:= P*n else P:= n; state:= true fi elif state then R:= R, P; count:= count+1; state:= false fi od: R; # Robert Israel, Jan 06 2020 MATHEMATICA Times @@ # & /@ DeleteCases[#, _?(! SquareFreeQ@ First@ # &)] &@ SplitBy[Range[140], SquareFreeQ] (* Michael De Vlieger, Jan 06 2020 *) CROSSREFS Cf. A005117. Sequence in context: A172530 A201237 A120436 * A334285 A068969 A335715 Adjacent sequences: A136739 A136740 A136741 * A136743 A136744 A136745 KEYWORD nonn AUTHOR Reinhard Zumkeller, Jan 20 2008 STATUS approved

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Last modified September 7 22:13 EDT 2024. Contains 375749 sequences. (Running on oeis4.)