a(n) = 2*t(n) + 3*t(n-1) + ... + (k+1)*t(n+1-k), where k=floor((n+1)/2) and t = A023531.

Terms

a(0) =0a(1) =2a(2) =3a(3) =0a(4) =2a(5) =3a(6) =4a(7) =5a(8) =8a(9) =3a(10) =4a(11) =5a(12) =6a(13) =9a(14) =11a(15) =13a(16) =15a(17) =6a(18) =7a(19) =10a(20) =12a(21) =14a(22) =16a(23) =18a(24) =20a(25) =22a(26) =26a(27) =13a(28) =15a(29) =17