A065739 Largest square <= sum of first n squares.

1, 4, 9, 25, 49, 81, 121, 196, 256, 361, 484, 625, 784, 961, 1225, 1444, 1764, 2025, 2401, 2809, 3249, 3721, 4225, 4900, 5476, 6084, 6889, 7569, 8464, 9409, 10404, 11236, 12321, 13456, 14884, 16129, 17424, 18769, 20449, 21904, 23716, 25281

Offset: 1

Author

Labos Elemer, Nov 15 2001

Keywords

• easy
• nonn

Links

• Harry J. Smith, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A048760, A000330, A065730-A065741.

Programs

PARI

a(n) = { sqrtint(n*(n+1)*(2*n+1)/6)^2 } \\ Harry J. Smith, Oct 29 2009

Formula

a(n) = A048760(A000330(n)).