OFFSET
1,1
LINKS
Valeryi Kuryshev, NMBRTHRY Archives, 2006
FORMULA
a(n) = nextprime(1 / (2 / abundancy(a(1) * ... * a(n-1)) - 1)) for n >= 4
EXAMPLE
a(5)=389 because abundancy(3*5*7*11*383) = 2.000013... > 2 and abundancy(3*5*7*11*389) = 1.999933... < 2.
PROG
(PARI) print(3); print(5); print(7); n=105; for(i=4, 7, k=nextprime(1 / (2 / abundancy(n) - 1)); print(k); );
CROSSREFS
KEYWORD
nonn
AUTHOR
Charles R Greathouse IV, Sep 05 2006
STATUS
approved