Squarefree numbers (A005117) with prime factors in a prime(k) + k progression.

Terms

a(0) =6a(1) =15a(2) =30a(3) =77a(4) =247a(5) =4819a(6) =7979a(7) =10057a(8) =12827a(9) =21353a(10) =24047a(11) =40363a(12) =60433a(13) =121411a(14) =146231a(15) =154729a(16) =211763a(17) =273509a(18) =301297a(19) =322499a(20) =346781a(21) =367063a(22) =382937a(23) =394091a(24) =415693a(25) =453727a(26) =485237a(27) =486719a(28) =579727a(29) =632579