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%I #7 Mar 23 2021 05:41:23
%S 127,173,181,257,281,359,563,569,577,719,751,1061,1381,1879,1901,4327,
%T 4759,5441,6397,6977,7207,7933,8387,8419,8521,9349,10009,10891,11311,
%U 11443,11467,12323,13567,13873,14369,14929,15299,15683,16073,17351,18041,18749,24407,24481,24767,25819,27067,27739
%N Primes p such that, if b is the sum of digits of p, y = p mod b and x = (p-y)/b, then p-x*y, p+x*y, x+y and x-y are all prime.
%H Robert Israel, <a href="/A342801/b342801.txt">Table of n, a(n) for n = 1..10000</a>
%e a(3) = 181 is a term because 181 is prime, with sum of digits b=10, y=1, x=18, and n-x*y=163, n+x*y=199, x+y=19, and x-y=17 are all prime.
%p filter:= proc(n) local b, x,y;
%p if not isprime(n) then return false fi;
%p b:= convert(convert(n,base,10),`+`);
%p if b <= 1 then return false fi;
%p y:= n mod b;
%p x:= (n-y)/b;
%p isprime(n-x*y) and isprime(n+x*y) and isprime(x+y) and isprime(x-y)
%p end proc:
%p select(filter, [2,seq(i,i=3..10^5,2)]);
%K nonn,base
%O 1,1
%A _J. M. Bergot_ and _Robert Israel_, Mar 21 2021
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