login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A063763 Composite integers k such that largest prime factor of k > sqrt(k). 7

%I

%S 6,10,14,15,20,21,22,26,28,33,34,35,38,39,42,44,46,51,52,55,57,58,62,

%T 65,66,68,69,74,76,77,78,82,85,86,87,88,91,92,93,94,95,99,102,104,106,

%U 110,111,114,115,116,117,118,119,122,123,124,129,130,133,134,136,138

%N Composite integers k such that largest prime factor of k > sqrt(k).

%C Subsequence of composite terms of A064052.

%H Ray Chandler, <a href="/A063763/b063763.txt">Table of n, a(n) for n = 1..10000</a> (first 1000 terms from Harry J. Smith)

%t Select[ Range[ 2, 160 ], !PrimeQ[ # ] && FactorInteger[ # ] [[ -1, 1 ] ] > Sqrt[ # ] & ]

%o (PARI) { n=0; for (m=2, 10^9, f=vecmax(component(factor(m), 1)); if(!isprime(m) && f^2 > m, write("b063763.txt", n++, " ", m); if (n==1000, break)) ) } \\ _Harry J. Smith_, Aug 30 2009

%Y Cf. A006530, A063538, A063539, A063762.

%K nonn

%O 1,1

%A _Robert G. Wilson v_, Aug 14 2001

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 March 2 08:39 EST 2021. Contains 341745 sequences. (Running on oeis4.)