A128040 a(n) = product of the primes which are <= the n-th squarefree positive integer. a(n) also is the LCM of the first n squarefree positive integers.

1, 2, 6, 30, 30, 210, 210, 2310, 30030, 30030, 30030, 510510, 9699690, 9699690, 9699690, 223092870, 223092870, 6469693230, 6469693230, 200560490130, 200560490130, 200560490130, 200560490130, 7420738134810, 7420738134810

Offset: 1

Author

Leroy Quet, May 07 2007

Keywords

• nonn

Crossrefs

Cf. A034386, A005117.

Programs

Maple

A005117 := proc(n) option remember; local a; if n =1 then 1; else a := A005117(n-1)+1 ; while not numtheory[issqrfree](a) do a := a+1 ; od: RETURN(a) ; fi ; end: A128040 := proc(n) lcm( seq(A005117(i),i=1..n) ) ; end: seq(A128040(n),n=1..30) ; # R. J. Mathar, Nov 01 2007

Extensions

More terms from R. J. Mathar, Nov 01 2007