OFFSET
1,1
COMMENTS
a(n) >= ceiling((prime(3*n)#)^(1/n)). - Chai Wah Wu, Sep 24 2020
EXAMPLE
a(4) = 1705.
p(3*4)#, which is the product of the first 12 primes, can be written as
s1 * s2 * s3 * s4 with
s1 = 5 * 11 * 31 = 1705,
s2 = 2 * 23 * 37 = 1702,
s3 = 3 * 19 * 29 = 1653,
s4 = 7 * 13 * 17 = 1547.
No such factorization is possible in sphenic numbers that are all < 1705.
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Bert Dobbelaere, Aug 29 2020
STATUS
approved