A168038 Squares closest to 2*n.

0, 1, 4, 4, 9, 9, 9, 16, 16, 16, 16, 25, 25, 25, 25, 25, 36, 36, 36, 36, 36, 36, 49, 49, 49, 49, 49, 49, 49, 64, 64, 64, 64, 64, 64, 64, 64, 81, 81, 81, 81, 81, 81, 81, 81, 81, 100, 100, 100, 100, 100, 100, 100, 100, 100, 100, 121, 121, 121, 121, 121, 121, 121, 121, 121

Offset: 0

Author

Zak Seidov, Nov 17 2009

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A002024, A093995.

Essentially partial sums of A198954.

Programs

Mathematica

Round[Sqrt[2*Range[0,120]]]^2

Python

from math import isqrt
def A168038(n): return (isqrt(n<<3)+1>>1)**2 # Chai Wah Wu, Jun 19 2024

Formula

a(n) = A002024(n)^2. - Chai Wah Wu, Jun 19 2024