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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: A080626 A015957 A074417 * A191506 A139007 A015486

Adjacent sequences:  A049647 A049648 A049649 * A049651 A049652 A049653

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane, May 05 2001

STATUS

approved

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Last modified December 21 05:22 EST 2014. Contains 252296 sequences.