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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.

%I A061427 #10 Jan 19 2023 01:41:52
%S A061427 3,19,33,91,139,193,319,333,391,913,931,1199,1339,1393,1919,1933,1991,
%T A061427 3139,3193,3319,3333,3391,3913,3931,9119,9133,9191,9313,9331,9911,
%U A061427 11399,11939,11993,13199,13339,13393,13919,13933,13991,19139,19193
%N 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.
%H A061427 Reinhard Zumkeller, <a href="/A061427/b061427.txt">Table of n, a(n) for n = 1..10000</a>
%e A061427 319 is a term as the geometric mean of digits is (3*1*9) = 27 = 3^3.
%t A061427 Select[Range[20000],GeometricMean[IntegerDigits[#]]==3&] (* _Harvey P. Dale_, Dec 11 2011 *)
%o A061427 (Haskell)
%o A061427 a061427 n = a061427_list !! (n-1)
%o A061427 a061427_list = g [1] where
%o A061427    g ds = if product ds == 3 ^ length ds
%o A061427           then foldr (\d v -> 10 * v + d) 0 ds : g (s ds) else g (s ds)
%o A061427    s [] = [1]; s (9:ds) = 1 : s ds; s (d:ds) = 3*d : ds
%o A061427 -- _Reinhard Zumkeller_, Jan 13 2014
%Y A061427 Cf. A061426-A061430.
%Y A061427 Cf. A174813.
%K A061427 nonn,base,easy
%O A061427 1,1
%A A061427 _Amarnath Murthy_, May 03 2001
%E A061427 More terms from Larry Reeves (larryr(AT)acm.org), May 16 2001