If a, b in sequence, so is ab+6.

Terms

a(0) =2a(1) =10a(2) =26a(3) =58a(4) =106a(5) =122a(6) =218a(7) =250a(8) =266a(9) =442a(10) =506a(11) =538a(12) =586a(13) =682a(14) =890a(15) =1018a(16) =1066a(17) =1082a(18) =1178a(19) =1226a(20) =1370a(21) =1514a(22) =1786a(23) =2042a(24) =2138a(25) =2170a(26) =2186a(27) =2362a(28) =2458a(29) =2506