login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A160857 n = Product[mPr for all r < m] , mPr = m!/(m-r)! , where m,r are both prime numbers. 0
1, 6, 1200, 22226400, 10041430291200000, 1113268229944758412288983040, 591370140954797306733044203963173317440962560, 21844691101536232598885758159278507307951395880466928082689720320 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,2

LINKS

Table of n, a(n) for n=2..9.

EXAMPLE

Primes = [2,3,5,7,...] Examples: a(1) = 1 (define); a(2) = 3P2 = 6 as 3 is 2nd prime and only prime less than 3 is 2; a(3) = 5P3 . 5P2 = 1200 as 5 is 3rd prime and primes less than 5 are {2,3}; a(4) = 7P5 . 7P3 . 7P2 = 22226400 ; and so on...

PROG

(PARI) a(n) = prod(i=1, n-1, prime(n)!/(prime(n)-prime(i))!); \\ Michel Marcus, Aug 11 2013

CROSSREFS

Cf. A000040.

Sequence in context: A185537 A113159 A159717 * A160005 A172923 A131675

Adjacent sequences:  A160854 A160855 A160856 * A160858 A160859 A160860

KEYWORD

nonn

AUTHOR

Pratik Deoghare (psdeoghare(AT)gmail.com), May 28 2009

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified October 17 18:19 EDT 2018. Contains 316292 sequences. (Running on oeis4.)