Number of length 3+2 0..n arrays with no pair in any consecutive three terms totalling exactly n.

Terms

a(0) =2a(1) =18a(2) =164a(3) =676a(4) =2262a(5) =5766a(6) =13064a(7) =25992a(8) =48170a(9) =82810a(10) =135852a(11) =212268a(12) =320894a(13) =468846a(14) =668432a(15) =929296a(16) =1267794a(17) =1696482a(18) =2236340a(19) =2903220a(20) =3723302a(21) =4716118a(22) =5913624a(23) =7339416a(24) =9031802a(25) =11018826a(26) =13345724a(27) =16045372a(28) =19170510a(29) =22759230