A068143 Triangular numbers which are products of triangular numbers larger than 1.

36, 45, 210, 300, 378, 630, 780, 990, 1485, 1540, 2850, 3240, 3570, 4095, 4851, 4950, 5460, 8778, 9180, 11781, 15400, 17955, 19110, 21528, 25200, 26565, 26796, 31878, 33930, 37128, 37950, 39060, 40755, 43956, 52650, 61425, 61776, 70125, 79800, 82215, 97020

Offset: 1

Author

Amarnath Murthy, Feb 23 2002

Keywords

• nonn

Examples

			210 is a term as 210 = 21*10 both triangular numbers.
300 is also a term since 300 = 3*10*10.
		

Links

• Pontus von Brömssen, Table of n, a(n) for n = 1..3597 (all terms below 10^12).

Crossrefs

Cf. A000217 (triangular numbers), A374374.

Except the first term, row n=3 of A374370 and row n=2 of A374498.

A188630 is a subsequence (only 2 factors allowed).

Extensions

Corrected and extended by Jon E. Schoenfield, Jul 23 2006

a(38)-a(41) from Pontus von Brömssen, Jul 02 2024