[seqfan] Re: Concordance to "What's Special About This Number?"

[zak seidov]

--- On Sun, 5/30/10, Richard Mathar <mathar at strw.leidenuniv.nl> wrote:
<skip>
> This may be refined to a further subset of these,
> "Perfect squares which are a product of two distinct
> triangular numbers"
> 
> 0, 36, 900, 1225, 7056, 32400, 41616, 44100, 88209, 108900, 298116,
 705600, 1368900, 1413721, 1498176, 2924100, 5336100, 
 8643600, 8820900, 9217296
> 

> 
> RJM

Or so :

  n^2 is a product of two distinct triangular numbers

0, 6, 30, 35, 84, 180, 204, 210, 297, 330, 546, 840, 1170, 1189, 
1224, 1710, 2310, 2940, 2970, 3036, 3230, 3900, 4914, 6090, 6930, 
7134, 7140, 7245, 7440, 8976, 10710, 12654, 14175, 14820, 16296, 
16380, 17220, 19866, 22770, 25172, 25944, 29103, 29400, 33150, 37206, 
40391, 41580, 41580, 41615, 46284, 51330, 56730, 57960, 58140

Zak