A151970 a(n) = smallest integer >= n which has only prime factors 3 and 5.

1, 3, 3, 5, 5, 9, 9, 9, 9, 15, 15, 15, 15, 15, 15, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 27, 27, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 45, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75, 75

Offset: 1

Author

N. J. A. Sloane, Aug 23 2009; corrected Mar 07 2012

Keywords

• nonn

Crossrefs

Cf. A130916, A134361, A151969.

Programs

R

f <- function(n) nextn(n, factors = c(3,5))
a <- matrix(1:256,ncol=1)
apply(a,1,f)