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A068143
Triangular numbers which are products of triangular numbers larger than 1.
9
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
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