OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
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.
MAPLE
filter:= proc(n) local b, x, y;
if not isprime(n) then return false fi;
b:= convert(convert(n, base, 10), `+`);
if b <= 1 then return false fi;
y:= n mod b;
x:= (n-y)/b;
isprime(n-x*y) and isprime(n+x*y) and isprime(x+y) and isprime(x-y)
end proc:
select(filter, [2, seq(i, i=3..10^5, 2)]);
CROSSREFS
KEYWORD
nonn,base
AUTHOR
J. M. Bergot and Robert Israel, Mar 21 2021
STATUS
approved