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Odd nonprimes n such that n+d+1 is prime for all divisors d of n.
1

%I #12 Aug 21 2016 17:31:50

%S 1,9,35,39,65,125,749,755,905,935,989,1469,1829,1859,2519,3161,4269,

%T 4859,5165,5699,6005,7319,8309,8759,9155,9869,11129,12819,12851,14141,

%U 14279,15539,15899,18689,19859,20019,25115,25535,26679,28049

%N Odd nonprimes n such that n+d+1 is prime for all divisors d of n.

%H Harvey P. Dale, <a href="/A187554/b187554.txt">Table of n, a(n) for n = 1..1000</a>

%F A120776(a(n+1)) = A120806(a(n+1)).

%e a(6) = 125 with divisors (1, 5, 25, 125) and the set of all n+d+1 is (127, 131, 151, 251) and these are all prime.

%t Select[Range[1,29001,2],!PrimeQ[#]&&AllTrue[#+Divisors[#]+1,PrimeQ]&] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Aug 21 2016 *)

%Y Cf. A120776, A120806, A120811.

%K nonn

%O 1,2

%A _Juri-Stepan Gerasimov_, Mar 26 2011