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A059391
a(1)=4; a(n) is the smallest number m > a(n-1) such that Omega(m + a(i)) = Omega(m) - Omega(a(i)) for i = 1..(n-1) where Omega(k) is the number of prime divisors of k counted with multiplicity.
1
4, 27, 208, 18630, 780856896
OFFSET
1,1
COMMENTS
Conjecture: Omega(a(n)) = n-th prime.
The conjecture is false because Omega(780856896) = 10. - Sean A. Irvine, Sep 19 2022
Next term > 10000000000. - Sean A. Irvine, Sep 20 2022
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Naohiro Nomoto, Jan 29 2001
EXTENSIONS
Name simplified and a(5) from Sean A. Irvine, Sep 19 2022
STATUS
approved