A113238 is the difference set of tribonacci numbers. A113188-A113194 deal with difference sets of Fibonacci numbers and Lucas numbers and primes in those difference sets.

a(n) = intersection of primes A000040 and difference set of tribonacci numbers A113238. Positive prime values of {A000073(i) - A000073(j) such that i>=j}.

EXAMPLE

a(1) = 2 because 4 - 2 = 2 where 4 and 2 are tribonacci numbers.

a(2) = 3 because 7 - 4 = 3 where 7 and 4 are tribonacci numbers.

a(3) = 5 because 7 - 2 = 5 where 7 and 2 are tribonacci numbers.

a(4) = 11 because 13 - 2 = 11 where 13 and 2 are tribonacci numbers.

a(5) = 17 because 24 - 7 = 17 where 24 and 7 are tribonacci numbers.