315420

Appears in sequences

• a(n) = (n+1)*(n+2)^2*(n+3)*(7*n^2 + 23*n + 20)/240.at n=13A114240
• Expansion of (1-5*x+6*x^2-x^3)/((1-x)*(1-2*x)*(1-3*x)*(1-4*x)).at n=9A246986
• For 1<=x<=n, 1<=y<=n, write gcd(x,y) = u*x+v*y with u,v minimal; a(n) = n^4*s, where s is the population variance of the values of u.at n=15A345687