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 A141090 Integral quotients of products of first k consecutive composites divided by their sums: products (dividends). 6
 4, 1728, 2903040, 12541132800, 115880067072000, 69528040243200000, 1807729046323200000, 43295255277764345856000000, 20188846756043686829592191472500736000000000, 989253491046140654650017382152536064000000000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Based on A141092. Compare with A140761 A159578 A140763 A116536. Take the first k composite numbers. If their product divided by their sum results in an integer, their product is a term of the sequence. - Harvey P. Dale, Apr 29 2018 LINKS Amiram Eldar, Table of n, a(n) for n = 1..93 FORMULA Find the products and sums of first k consecutive composites. When the product divided by the sum produces an integral quotient, add product to sequence. EXAMPLE a(3) = 2903040 because 4*6*8*9*10*12*14 = 2903040 and 4+6+8+9+10+12+14 = 63; 2903040/63 = 46080, integral -- 2903040 is added to the sequence. MATHEMATICA With[{c=Select[Range[100], CompositeQ]}, Table[If[IntegerQ[ Times@@Take[ c, n]/Total[ Take[ c, n]]], Times@@ Take[ c, n], 0], {n, Length[c]}]]/.(0-> Nothing) (* Harvey P. Dale, Apr 29 2018 *) CROSSREFS Cf. A196415, A141089, A141091, A141092. Sequence in context: A160225 A316484 A278794 * A307580 A255268 A079402 Adjacent sequences:  A141087 A141088 A141089 * A141091 A141092 A141093 KEYWORD easy,nonn AUTHOR Enoch Haga, Jun 01 2008 EXTENSIONS Checked by N. J. A. Sloane, Oct 02 2011 Edited by N. J. A. Sloane, Apr 29 2018 STATUS approved

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Last modified December 1 14:10 EST 2021. Contains 349430 sequences. (Running on oeis4.)