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A231558 Odd composite numbers n, such that n, n+d, n*d and n/d are all odious (A000069) for every divisor d of n. 2

%I #12 Nov 15 2013 03:18:41

%S 217,511,889,949,1957,2041,2263,2413,2869,3113,3133,3481,3991,5201,

%T 5761,7813,7903,8071,8137,8773,10519,10609,11377,11879,12191,12313,

%U 12871,15127,15223,16177,19561,19733,19879,21151,23077,23233,23449,23573,26221,27469

%N Odd composite numbers n, such that n, n+d, n*d and n/d are all odious (A000069) for every divisor d of n.

%C All terms are in A079523.

%H Peter J. C. Moses, <a href="/A231558/b231558.txt">Table of n, a(n) for n = 1..10000</a>

%e Let n=217. Its divisors are {1,7,31,217}. We see that all numbers 217+1=218, 217+7=224, 217+31=248, 217+217=434, 217/1=217, 217/7=31, 217/31=7, 217/217=1, 217*1=217, 217*7=1519, 217*31=6727, 217*217=47089 are odious. Thus 217 is in the sequence.

%Y Cf. A231271, A228436, A000069, A079523.

%K nonn,base

%O 1,1

%A _Vladimir Shevelev_ and _Peter J. C. Moses_, Nov 11 2013

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Last modified April 25 10:01 EDT 2024. Contains 371967 sequences. (Running on oeis4.)