cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

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.

Original entry on oeis.org

217, 511, 889, 949, 1957, 2041, 2263, 2413, 2869, 3113, 3133, 3481, 3991, 5201, 5761, 7813, 7903, 8071, 8137, 8773, 10519, 10609, 11377, 11879, 12191, 12313, 12871, 15127, 15223, 16177, 19561, 19733, 19879, 21151, 23077, 23233, 23449, 23573, 26221, 27469
Offset: 1

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All terms are in A079523.

Examples

			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.
		

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