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

1,1

Links

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

Example

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

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).

Sequence in context: A195528 A144291 A375824 * A264961 A188630 A167310

Adjacent sequences: A068140 A068141 A068142 * A068144 A068145 A068146

Keyword

nonn

Author

Amarnath Murthy, Feb 23 2002

Extensions

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

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

Status

approved