

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
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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



