|
| |
|
|
A141092
|
|
Integral quotients of products of consecutive composites divided by their sums: Integral quotients.
|
|
9
| |
|
|
1, 64, 46080, 111974400, 662171811840, 310393036800000, 7230916185292800, 108238138194410864640000, 23835710455777670400935290994688000000000, 1104077556971139123493322971152384000000000
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 1,2
|
|
|
COMMENTS
| Find the products and sums of consecutive composites. When the products divided by the sums produce integral quotients, add terms to sequence.
|
|
|
LINKS
| Reinhard Zumkeller, Table of n, a(n) for n = 1..90
|
|
|
FORMULA
| a(n) = A036691(A196415(n)) / A053767(A196415(n)). [Reinhard Zumkeller, Oct 03 2011]
|
|
|
EXAMPLE
| a(3)=46080 because 4*6*8*9*10*12*14=2903040 and 4+6+8+9+10+12+14=63; 2903040/63=46080, integral -- 46080 is added to the sequence.
|
|
|
PROG
| (Haskell)
import Data.Maybe (catMaybes)
a141092 n = a141092_list !! (n-1)
a141092_list = catMaybes $ zipWith div' a036691_list a053767_list where
div' x y | m == 0 = Just x'
| otherwise = Nothing where (x', m) = divMod x y
-- Reinhard Zumkeller, Oct 03 2011
|
|
|
CROSSREFS
| Cf. A196415, A141089, A141090, A141091.
Compare with A140761, A159578, A140763, A116536.
Cf. A116536.
Sequence in context: A013743 A098843 A159400 * A016830 A103346 A123394
Adjacent sequences: A141089 A141090 A141091 * A141093 A141094 A141095
|
|
|
KEYWORD
| easy,nonn
|
|
|
AUTHOR
| Enoch Haga (Enokh(AT)comcast.net), Jun 01 2008
|
|
|
EXTENSIONS
| Checked by N. J. A. Sloane, Oct 02 2011.
|
| |
|
|
