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Triangular numbers for which the product of the digits is a square.
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%I #5 Jul 21 2016 18:37:57

%S 0,1,10,28,55,66,91,105,120,190,210,300,406,595,630,703,780,820,903,

%T 990,1035,1081,1128,1326,1540,1770,1830,2016,2080,2211,2346,2701,2850,

%U 3003,3081,3160,3240,3403,3486,3570,4005,4095,4560,4950,5050,5151,5460,5995

%N Triangular numbers for which the product of the digits is a square.

%e 3486 is in the sequence because (1) it is a triangular number and (2) the product of its digits 3*4*8*6=576 is a square.

%t Select[Accumulate[Range[0,150]],IntegerQ[Sqrt[Times@@IntegerDigits[#]]]&] (* _Harvey P. Dale_, Jul 21 2016 *)

%Y Cf. A000217.

%K base,nonn

%O 0,3

%A Luc Stevens (lms022(AT)yahoo.com), Apr 26 2006