660100

Appears in sequences

• Long leg B of primitive Pythagorean triangles such that perimeters are Averages of twin prime pairs, q=p+1, a=q^2-p^2, c=q^2+p^2, b=2*p*q, s=a+b+c, s-+1 are primes.at n=30A155174
• The 4-tuple (2, ((2*n+1)^2-1)/2, ((2*n+3)^2-1)/2, a(n)), where a(n) = 4*(3 + 20n + 42n^2 + 32n^3 + 8n^4), has Diophantus's property that the product of any two distinct terms plus one is a square.at n=10A160372
• a(n) = binomial(n^2,3)/(2*n).at n=23A201106