a(n) = (A114043(n) - 1)/2.

Terms

a(0) =0a(1) =3a(2) =14a(3) =43a(4) =100a(5) =209a(6) =374a(7) =641a(8) =1020a(9) =1553a(10) =2246a(11) =3197a(12) =4372a(13) =5911a(14) =7778a(15) =10037a(16) =12728a(17) =16043a(18) =19862a(19) =24467a(20) =29728a(21) =35777a(22) =42626a(23) =50625a(24) =59520a(25) =69675a(26) =80966a(27) =93627a(28) =107568a(29) =123345