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.
%I A295075 #15 Nov 15 2017 05:41:47 %S A295075 3,5,7,8,9,11,13,14,15,17,19,20,21,23,25,26,27,29,31,32,33,35,37,38, %T A295075 39,41,43,44,45,47,49,50,51,53,55,56,57,59,61,62,63,64,65,67,68,69,71, %U A295075 73,74,75,77,79,80,81,83,85,86,87,89,91,92,93,94,95,97,98,99 %N A295075 Numbers k such that d + k/d is never prime for any divisor d of k. %C A295075 Numbers k such that A282849(k) = 0. %H A295075 Robert Israel, <a href="/A295075/b295075.txt">Table of n, a(n) for n = 1..10000</a> %p A295075 remove(n -> ormap(t -> isprime(t+n/t), numtheory:-divisors(n)), [$1..100]); # _Robert Israel_, Nov 14 2017 %t A295075 Select[Range@ 100, Function[k, NoneTrue[Divisors@ k, PrimeQ[# + k/#] &]]] (* _Michael De Vlieger_, Nov 13 2017 *) %o A295075 (PARI) isok(n) = sumdiv(n, d, isprime(d+n/d)) == 0; %Y A295075 Cf. A282849 (number of divisors of n such that d + n/d is prime), A080715 (d + n/d is prime for every divisor d of n). %Y A295075 Includes all elements > 2 of A047255. %K A295075 nonn %O A295075 1,1 %A A295075 _Michel Marcus_, Nov 13 2017