A094337 a(n) = floor((product of composites among next n numbers)/(product of primes among next n numbers)).

0, 1, 4, 1, 617, 112, 845, 25376, 2985, 314, 1597052, 138874, 1173486218, 63368255819, 4370224539, 281949970, 5377913733006, 376453961310474, 7345939461247630, 572983277977315172, 27950403803771471, 1300018781570766

Offset

1,3

Comments

The products of primes in the denominators are in A068111 for n>=2. - R. J. Mathar, Jul 27 2007

Links

Table of n, a(n) for n=1..22.

Example

a(3) = floor((4*6)/5) = 4.
a(4) = floor(6*8/(5*7)) = floor(48/35) = 1.
a(5) = floor(6*8*9*10/7) = floor(4320/7) = 617.

Maple

A094337 := proc(n) local nup, ndown, i ; nup := 0 ; ndown := 0 ; for i from n+1 to 2*n do if isprime(i) then if ndown = 0 then ndown :=i ; else ndown := ndown*i ; fi ; else if nup = 0 then nup := i ; else nup := nup*i ; fi ; fi ; od; floor(nup/ndown) ; end: seq(A094337(n), n=1..24) ; # R. J. Mathar, Jul 27 2007

Crossrefs

Sequence in context: A347554 A298939 A240098 * A345313 A038019 A164804

Adjacent sequences: A094334 A094335 A094336 * A094338 A094339 A094340

Keyword

nonn

Author

Amarnath Murthy, May 17 2004

Extensions

Corrected and extended by R. J. Mathar, Jul 27 2007

Status

approved