2821500

Appears in sequences

• Triangular numbers which are 10-almost primes.at n=20A101744
• Triangular numbers that are the product of 4 distinct triangular numbers greater than 1.at n=14A226501
• Triangular numbers that can be represented as a product of two triangular numbers greater than 1, and as a product of three triangular numbers greater than 1.at n=21A295769
• 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.at n=9A296097
• a(n) is the smallest triangular number (A000217) that can be represented as a product of k triangular numbers greater than 1 for all k = 1,2,...,n. a(n)=-1 if no such triangular number exists.at n=5A296098
• Hexagonal numbers that are products of smaller hexagonal numbers.at n=15A374373