8820900

Appears in sequences

• a(n) = product{k=1 to n} (k-th integer from among those positive integers which are coprime to (n+1-k)).at n=8A130767
• Perfect squares that are a product of two distinct triangular numbers.at n=18A169836
• Perfect powers k (exponent greater than 1) such that k-1 and k+1 are both semiprime.at n=31A276564
• a(n) = Product_{d|n} A019565(phi(d)), where phi is Euler totient function A000010.at n=53A332824