[seqfan] Re: Leyland Numbers Puzzle

[Hans Havermann]

"The 13 approximately equal {(240240,2), (120120,4), (80080,8), (60060,16), (48048,32), (40040,64), (34320,128), (30030,256), (24024,1024), (21840,2048), (20020,4096), (18480,8192), (17160,16384)} Leyland pairs are conspicuously missing (x,512). Can anyone put their finger on why that should be?"

I think I’ve got it. For (x,512) to be roughly equal to the rest, x would have to be 80080/3 which is not an integer.