A186299 (A007521(n)-1)/2.
2, 6, 14, 18, 26, 30, 50, 54, 74, 78, 86, 90, 98, 114, 134, 138, 146, 158, 174, 186, 194, 198, 210, 230, 254, 270, 278, 306, 326, 330, 338, 350, 354, 366, 378, 386, 398, 410, 414, 426, 438, 470, 498, 506, 510, 530, 534, 546, 554, 558, 590, 606
Offset: 1
Keywords
Formula
a(n) = A186300(n)-1.