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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
OFFSET
1,1
COMMENTS
Based on A141092.
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
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
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