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

 

Logo

Annual Appeal: Please make a donation (tax deductible in USA) to keep the OEIS running. Over 5000 articles have referenced us, often saying "we discovered this result with the help of the OEIS".

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A049650 Compositorial numbers (A036691) + 1. 2
2, 5, 25, 193, 1729, 17281, 207361, 2903041, 43545601, 696729601, 12541132801, 250822656001, 5267275776001, 115880067072001, 2781121609728001, 69528040243200001, 1807729046323200001, 48808684250726400001, 1366643159020339200001 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

This is to Euclid numbers (A006862): 1 + product of first n consecutive primes, as nonprimes (A018252) are to primes (A000040). These numbers - 1, times the appropriate Euclid numbers - 1, are the factorials. Primes in this sequence include a(1) = 2, a(2) = 5, a(4) = 193, a(8) = 2903041, a(12) = 250822656001, a(17) = 1807729046323200001. - Jonathan Vos Post, Jun 07 2008

LINKS

Table of n, a(n) for n=0..18.

Hisanori Mishima, Factorizations of many number sequences

Hisanori Mishima, Factorizations of many number sequences

FORMULA

a(n) = 1 + PRODUCT[i=1..n] A018252(i) = 1 + PRODUCT[j=1..n] (j=1 or j>1 and j is not in A000040}. - Jonathan Vos Post, Jun 07 2008

CROSSREFS

Cf. A036691, A060880, A006862, A036691.

Sequence in context: A268356 A074417 A268120 * A191506 A139007 A015486

Adjacent sequences:  A049647 A049648 A049649 * A049651 A049652 A049653

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 05 2001

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 December 9 12:22 EST 2016. Contains 278971 sequences.