1, 4, 12, 26, 48, 76, 114, 152, 206, 252, 318, 382, 458, 544, 622, 718, 818, 924, 1042, 1152, 1280, 1422, 1544, 1710, 1840, 2012, 2170, 2344, 2520, 2712, 2884, 3108, 3278, 3526, 3704, 3956, 4164, 4424, 4642, 4916, 5134, 5446, 5658, 5992, 6212, 6558, ････
簡単な式で表わせるんでしょうかね？

Coordination sequence T1 for Keatite.
http://oeis.org/A009844