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Geometric mean of the digits = 2. In other words, the product of the digits is = 2^k where k is the number of digits.
8

%I #9 Jan 19 2023 01:41:24

%S 2,14,22,41,118,124,142,181,214,222,241,412,421,811,1128,1144,1182,

%T 1218,1224,1242,1281,1414,1422,1441,1812,1821,2118,2124,2142,2181,

%U 2214,2222,2241,2412,2421,2811,4114,4122,4141,4212,4221,4411,8112,8121,8211

%N Geometric mean of the digits = 2. In other words, the product of the digits is = 2^k where k is the number of digits.

%H Reinhard Zumkeller, <a href="/A061426/b061426.txt">Table of n, a(n) for n = 1..10000</a>

%e 124 is a term as the geometric mean of digits is (1*2*4) = 8 = 2^3.

%o (Haskell)

%o a061426 n = a061426_list !! (n-1)

%o a061426_list = g [1] where

%o g ds = if product ds == 2 ^ length ds

%o then foldr (\d v -> 10 * v + d) 0 ds : g (s ds) else g (s ds)

%o s [] = [1]; s (8:ds) = 1 : s ds; s (d:ds) = 2*d : ds

%o -- _Reinhard Zumkeller_, Jan 13 2014

%Y Cf. A061427-A061430. A069512 gives another version.

%Y Cf. A028846.

%K nonn,base,easy

%O 1,1

%A _Amarnath Murthy_, May 03 2001

%E More terms from _Erich Friedman_, May 08 2001