A065730 Largest square <= n-th prime.

1, 1, 4, 4, 9, 9, 16, 16, 16, 25, 25, 36, 36, 36, 36, 49, 49, 49, 64, 64, 64, 64, 81, 81, 81, 100, 100, 100, 100, 100, 121, 121, 121, 121, 144, 144, 144, 144, 144, 169, 169, 169, 169, 169, 196, 196, 196, 196, 225, 225, 225, 225, 225, 225, 256, 256, 256, 256, 256

Offset: 1

Author

Labos Elemer, Nov 15 2001

Keywords

• easy
• nonn

Comments

For n > 2: a(n) = A257053(n,0). - Reinhard Zumkeller, Apr 15 2015

Links

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

Crossrefs

Cf. A048760, A000040, A065731-A065741.

Cf. A257053.

Programs

Haskell

a065730 = a048760 . a000040  -- Reinhard Zumkeller, Apr 15 2015

Magma

[Floor(Sqrt(NthPrime(n)))^2: n in [1..70]]; // Vincenzo Librandi, Jan 05 2018

Mathematica

Table[Floor[Sqrt@ Prime@ n]^2, {n, 60}] (* Michael De Vlieger, Jul 03 2016 *)

PARI

a(n) = { sqrtint(prime(n))^2 } \\ Harry J. Smith, Oct 28 2009

Formula

a(n) = A048760(A000040(n)).