%I #16 Dec 08 2018 03:00:20

%S 1,4,9,11,14,19,22,33,41,91,111,114,119,122,133,141,191,212,221,313,

%T 331,411,911,1111,1114,1119,1122,1133,1141,1191,1212,1221,1313,1331,

%U 1411,1911,2112,2121,2211,3113,3131,3311,4111,9111,11111,11114,11119

%N Product of digits of n is a nonzero single-digit square.

%C I.e., the product of digits is 1, 4, or 9. - _Franklin T. Adams-Watters_, Sep 27 2016

%t Select[Range[12000],MemberQ[{1,4,9},Times@@IntegerDigits[#]]&] (* _Harvey P. Dale_, Jan 22 2016 *)

%Y Cf. A007954, A028845, A028839, A002275 (a subsequence).

%K nonn,base

%O 1,2

%A _Patrick De Geest_, Jun 15 1999