A026231 a(n) = n-th number k such that t(k) = s(k) - 1, where s = A026142, t = A026166.

8, 17, 20, 26, 35, 44, 47, 53, 56, 62, 71, 74, 80, 89, 98, 101, 107, 116, 125, 128, 134, 137, 143, 152, 155, 161, 164, 170, 179, 182, 188, 197, 206, 209, 215, 218, 224, 233, 236, 242, 251, 260, 263, 269, 278, 287, 290, 296, 299