A296097 Triangular numbers that can be represented as a product of two triangular numbers greater than 1, as a product of three triangular numbers greater than 1, and as a product of four triangular numbers greater than 1.

25200, 61425, 145530, 500500, 749700, 828828, 1185030, 2031120, 2162160, 2821500, 4573800, 5364450, 13857480, 17907120, 20991960, 21783300, 24643710, 27162135, 29610360, 30933045, 34283340, 37191000, 40901490, 60769800, 64292130, 71216145, 76576500, 90041490

Offset: 1

Author

Alex Ratushnyak, Dec 04 2017

Keywords

• nonn

Comments

Triangular numbers in the products need not be distinct, that is, duplicates in the products are allowed.

A subsequence of A188630 and of A295769.

Examples

			25200 = 210 * 120 = 120 * 21 * 10 = 28 * 15 * 10 * 6.
		

Crossrefs

Cf. A000217, A188630, A295769.