The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A029559 Quasi-Carmichael numbers to base 4: squarefree composites n such that (n,2*3) = 1 and prime p|n ==> p-4|n-4. 2

%I #15 May 21 2013 11:15:00

%S 1705,7015,31369,53599,77809,215635,244885,248239,346801,568879,

%T 662935,898105,2151769,2240515,2782579,9480829,10665265,11219485,

%U 13644085,13929205,16549579,17782879,21592289,29354329,30075565,35448439,39792379

%N Quasi-Carmichael numbers to base 4: squarefree composites n such that (n,2*3) = 1 and prime p|n ==> p-4|n-4.

%C If multiples of 2 and 3 are not excluded, then terms like 6, 10, 15, 30, 70, 130, 165,... belong to the sequence. - _Giovanni Resta_, May 21 2013

%H Giovanni Resta, <a href="/A029559/b029559.txt">Table of n, a(n) for n = 1..372</a> (terms < 10^12)

%H <a href="/index/Ca#Carmichael">Index entries for sequences related to Carmichael numbers.</a>

%t qcm[n_, d_] := Block[{p, e}, {p, e} = Transpose@FactorInteger@n; Length[p] > 1 && Max[e] == 1 && d < Min[p] && And @@ IntegerQ /@ ((n - d)/(p - d))]; Select[Range[10^6], qcm[#, 4] &] (* _Giovanni Resta_, May 21 2013 *)

%K nonn

%O 1,1

%A _David W. Wilson_

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

Last modified May 23 05:11 EDT 2024. Contains 372758 sequences. (Running on oeis4.)