55216

Appears in sequences

• 4-dimensional analog of centered polygonal numbers: a(n) = n(n+1)*(n^2+n+4)/12.at n=28A006007
• Area of annuli of consecutive integer thickness.at n=25A114378
• Numbers k such that k^2 divides 15^k-1.at n=31A128395
• a(n) = n*(n + 1)*(5*n - 4)/2.at n=28A237616
• Numbers x such that there exist three integers 0<x<=y<=z and t>0 such that sigma(x)^2 = sigma(y)^2 = sigma(z)^2 = x^2 + y^2 + z^2 + t^2.at n=32A385531