a(1) = 1; a(2) = 9; for n>2, a(n) = smallest number of the form 4k+1 and a(n) > a(n-1) such that the pairwise sums of elements are all semiprimes.

A175532

a(1) = 1; a(2) = 9; for n>2, a(n) = smallest number of the form 4k+1 and a(n) > a(n-1) such that the pairwise sums of elements are all semiprimes.

Terms

    a(0) =1a(1) =9a(2) =13a(3) =25a(4) =133a(5) =193a(6) =18673a(7) =57313a(8) =1032313a(9) =4387273a(10) =3450430573a(11) =11717813053a(12) =21691948933

External references