

A061427


Geometric mean of the digits = 3. In other words, the product of the digits is = 3^k where k is the number of digits.


7



3, 19, 33, 91, 139, 193, 319, 333, 391, 913, 931, 1199, 1339, 1393, 1919, 1933, 1991, 3139, 3193, 3319, 3333, 3391, 3913, 3931, 9119, 9133, 9191, 9313, 9331, 9911, 11399, 11939, 11993, 13199, 13339, 13393, 13919, 13933, 13991, 19139, 19193
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


LINKS



EXAMPLE

319 is a term as the geometric mean of digits is (3*1*9) = 27 = 3^3.


MATHEMATICA

Select[Range[20000], GeometricMean[IntegerDigits[#]]==3&] (* Harvey P. Dale, Dec 11 2011 *)


PROG

(Haskell)
a061427 n = a061427_list !! (n1)
a061427_list = g [1] where
g ds = if product ds == 3 ^ length ds
then foldr (\d v > 10 * v + d) 0 ds : g (s ds) else g (s ds)
s [] = [1]; s (9:ds) = 1 : s ds; s (d:ds) = 3*d : ds


CROSSREFS



KEYWORD

nonn,base,easy


AUTHOR



EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001


STATUS

approved



