198135

Appears in sequences

• Tritriangular numbers: a(n) = binomial(binomial(n,2),2) = n*(n+1)*(n-1)*(n-2)/8.at n=36A050534
• Triangular numbers that are 1/7 of triangular numbers.at n=5A077399
• Triangular numbers k such that phi(k) is a square number, where phi(k) is the Euler totient function (A000010).at n=15A287473
• 32*a(n) is the denominator of the squared circumradius of a cyclic quadrilateral with sides n, n+1, n+2, n+3.at n=33A351697