This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A151970 #4 Mar 30 2012 16:51:07 %S A151970 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, %T A151970 27,45,45,45,45,45,45,45,45,45,45,45,45,45,45,45,45,45,45,75,75,75,75, %U A151970 75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75,75 %N A151970 a(n) = smallest integer >= n which has only prime factors 3 and 5. %o A151970 (R) f <- function(n) nextn(n, factors = c(3,5)) %o A151970 a <- matrix(1:256,ncol=1) %o A151970 apply(a,1,f) %Y A151970 Cf. A130916, A134361, A151969. %K A151970 nonn %O A151970 1,2 %A A151970 _N. J. A. Sloane_, Aug 23 2009; corrected Mar 07 2012