login
A104588
Product of primes less than or equal to sqrt(n).
2
1, 1, 1, 2, 2, 2, 2, 2, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 30, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210, 210
OFFSET
1,4
FORMULA
a(n) = A034386(A000196(n)).
For n>0, #p(n) appears {(p(n+1))^2 - (p(n))^2} times [from n=(p(n))^2 to n=(p(n+1))^2 - 1, inclusive], i.e. A002110(n) appears A069482(n) times [from n=A001248(n) to n=A001248(n+1)-1, inclusive]
MAPLE
A104588 := proc(n)
end proc: # R. J. Mathar, Jul 28 2013
PROG
(PARI) a(n) = {pr = 1; forprime (p=2, sqrtint(n), pr *= p; ); return (pr); } \\ Michel Marcus, Jul 28 2013
CROSSREFS
Sequence in context: A221838 A343122 A338869 * A157279 A214080 A278241
KEYWORD
nonn
AUTHOR
Lekraj Beedassy, Mar 17 2005
STATUS
approved