A074695 Greatest common divisor of n and floor(n^(1/2))^2.

1, 1, 1, 4, 1, 2, 1, 4, 9, 1, 1, 3, 1, 1, 3, 16, 1, 2, 1, 4, 1, 2, 1, 8, 25, 1, 1, 1, 1, 5, 1, 1, 1, 1, 5, 36, 1, 2, 3, 4, 1, 6, 1, 4, 9, 2, 1, 12, 49, 1, 1, 1, 1, 1, 1, 7, 1, 1, 1, 1, 1, 1, 7, 64, 1, 2, 1, 4, 1, 2, 1, 8, 1, 2, 1, 4, 1, 2, 1, 16, 81, 1, 1, 3, 1, 1, 3, 1, 1, 9, 1, 1, 3, 1, 1, 3, 1, 1, 9, 100

Offset: 1

Author

Reinhard Zumkeller, Sep 03 2002

Keywords

• nonn

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000196, A000290, A048760.

Cf. A258613, A258614.

Programs

Haskell

a074695 n = gcd n $ a048760 n  -- Reinhard Zumkeller, Jun 05 2015

Mathematica

Table[GCD[n,Floor[Sqrt[n]]^2],{n,100}] (* Harvey P. Dale, Aug 12 2018 *)

PARI

a(n) = gcd(n, sqrtint(n)^2); \\ Amiram Eldar, Nov 19 2024

Formula

a(n) = GCD(n, A048760(n)).

a(n) = n iff n is a square.

a(A258613(n)) = 1; a(A258614(n)) > 1. - Reinhard Zumkeller, Jun 05 2015