Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #11 Jul 07 2024 13:16:28
%S 2,3,5,11,17,23,31,37,43,79,193,491,503,653,883,1201,10607,19009,
%T 19469,19489,34963,35809,46499,223273,223313,391231,409817,410731,
%U 532159,634061,754549,1383769,1389533,2552621,2555753,3311233,4477453,4700621
%N Prime differences of tribonacci numbers.
%C 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.
%F Intersection of primes A000040 and difference set of tribonacci numbers A113238. Positive prime values of {A000073(i) - A000073(j) such that i>j}.
%e a(1) = 2 because 4 - 2 = 2 where 4 and 2 are tribonacci numbers.
%e a(2) = 3 because 7 - 4 = 3 where 7 and 4 are tribonacci numbers.
%e a(3) = 5 because 7 - 2 = 5 where 7 and 2 are tribonacci numbers.
%e a(4) = 11 because 13 - 2 = 11 where 13 and 2 are tribonacci numbers.
%e a(5) = 17 because 24 - 7 = 17 where 24 and 7 are tribonacci numbers.
%t Select[Union[Flatten[Differences/@Subsets[Drop[LinearRecurrence[{1, 1, 1}, {0, 0, 1}, 29],2],{2}]]],PrimeQ] (* _James C. McMahon_, Jun 23 2024 *)
%Y Cf. A000040, A000073, A113188-A113194, A113238.
%K easy,nonn
%O 1,1
%A _Jonathan Vos Post_, Oct 19 2005