login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A258614 Numbers m having with the largest square <= m a common divisor > 1. 3

%I

%S 4,6,8,9,12,15,16,18,20,22,24,25,30,35,36,38,39,40,42,44,45,46,48,49,

%T 56,63,64,66,68,70,72,74,76,78,80,81,84,87,90,93,96,99,100,102,104,

%U 105,106,108,110,112,114,115,116,118,120,121,132,143,144,146,147

%N Numbers m having with the largest square <= m a common divisor > 1.

%H Reinhard Zumkeller, <a href="/A258614/b258614.txt">Table of n, a(n) for n = 1..10000</a>

%F A074695(a(n)) > 1.

%e a(11) = 24: GCD(24,A048760(24)) = GCD(24,16) = 4 > 1;

%e a(12) = 25: GCD(25,A048760(25)) = GCD(25,25) = 25 > 1;

%e but GCD(26,A048760(26)) = GCD(26,25) = 1, therefore 26 isn't a term.

%o (Haskell)

%o a258614 n = a258614_list !! (n-1)

%o a258614_list = filter ((> 1) . a074695) [1..]

%o (PARI) isok(m) = gcd(m, sqr(sqrtint(m))) > 1; \\ _Michel Marcus_, Jan 23 2022

%Y Cf. A074695, A048760, A258613 (complement).

%K nonn,changed

%O 1,1

%A _Reinhard Zumkeller_, Jun 05 2015

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified January 27 12:02 EST 2022. Contains 350607 sequences. (Running on oeis4.)