Sum of the nonnegative terms in the n-th row of A365968.

Terms

a(0) =0a(1) =1a(2) =4a(3) =12a(4) =36a(5) =98a(6) =250a(7) =616a(8) =1484a(9) =3508a(10) =8140a(11) =18620a(12) =42164a(13) =94632a(14) =210518a(15) =464840a(16) =1020556a(17) =2229014a(18) =4843316a(19) =10476164a(20) =22576728a(21) =48489154a(22) =103790370a(23) =221484824a(24) =471427432a(25) =1001027226a(26) =2120503144a(27) =4482083616a(28) =9455815160a(29) =19913405076