A228174 Numbers representable as x^x * y^y, with x > y > 1.

108, 1024, 6912, 12500, 84375, 186624, 800000, 1259712, 3294172, 11943936, 22235661, 67108864, 145800000, 210827008, 452984832, 1549681956, 2573571875, 4294967296, 10460353203, 38423222208, 40000000000, 52428800000, 99179645184, 270000000000, 782757789696

Offset: 1

Author

Alex Ratushnyak, Nov 02 2013

Keywords

• nonn

Comments

A subsequence of A156223.

Examples

			a(7) = 4^4 * 5^5 = 800000.
		

Crossrefs

Cf. A000312, A156223.

Programs

Mathematica

nn = 12; Select[Rest[Union[Flatten[Table[If[x > y, x^x*y^y, 0], {x, 3, nn}, {y, 2, nn - 1}]]]], # <= 4*nn^nn &] (* T. D. Noe, Nov 04 2013 *)