Duplicate of A114146.

Terms

a(0) =1a(1) =2a(2) =14a(3) =58a(4) =174a(5) =402a(6) =838a(7) =1498a(8) =2566a(9) =4082a(10) =6214a(11) =8986a(12) =12790a(13) =17490