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A080361
a(n) is the difference between the largest and the smallest positive integers x such that the number of unitary-prime-divisors of x! equals n. Same as the difference between the largest and the smallest positive integers x such that the number of primes in (x/2,x] equals n.
1
8, 13, 15, 21, 15, 15, 13, 9, 25, 27, 5, 23, 39, 37, 27, 21, 7, 45, 37, 39, 39, 1, 21, 17, 11, 35, 27, 53, 35, 17, 19, 27, 29, 9, 11, 11, 5, 21, 43, 27, 11, 69, 61, 63, 15, 5, 1, 5, 33, 29, 27, 5, 5, 17, 57, 43, 47, 17, 25, 51, 47, 11, 3, 25, 27, 23, 77, 57, 35, 19, 29, 37, 27, 23, 9
OFFSET
1,1
FORMULA
a(n)=Max{x; Pi[x]-Pi[x/2]=n}-Min{x; Pi[x]-Pi[x/2]=n}=A080360[n]-A080359[n].
CROSSREFS
Cf. A104272 Ramanujan primes. [From Jonathan Sondow, Aug 10 2008]
Sequence in context: A271720 A243436 A214412 * A054295 A328241 A287159
KEYWORD
nonn
AUTHOR
Labos Elemer, Feb 21 2003
EXTENSIONS
Definition corrected by Jonathan Sondow, Aug 10 2008
Typo in formula corrected by Daniel Forgues, Aug 06 2009
STATUS
approved