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A029555 Quasi-Carmichael numbers to base 8: squarefree composites n such that (n,2*3*5*7) = 1 and prime p|n ==> p-8|n-8. 2

%I #15 May 21 2013 11:16:56

%S 143,17963,46943,64583,85877,128843,155933,208403,209933,1992383,

%T 2155283,2237183,2973113,3535883,3697733,3834683,4858631,8060753,

%U 10109093,11841383,12344813,13107263,15453383,16122653,16533749,18401183,18742823

%N Quasi-Carmichael numbers to base 8: squarefree composites n such that (n,2*3*5*7) = 1 and prime p|n ==> p-8|n-8.

%C If multiples of 2, 3, 5 and 7 are not excluded, then terms like 14, 35, 77, 110, 170, 273,... belong to the sequence. - _Giovanni Resta_, May 21 2013

%H Giovanni Resta, <a href="/A029555/b029555.txt">Table of n, a(n) for n = 1..589</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[#, 8] &] (* _Giovanni Resta_, May 21 2013 *)

%K nonn

%O 1,1

%A _David W. Wilson_

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Last modified February 23 11:40 EST 2024. Contains 370283 sequences. (Running on oeis4.)