a(n) = Sum_{k=0..n} (k+1) * A026714(n, k).

Terms

a(0) =1a(1) =3a(2) =10a(3) =30a(4) =87a(5) =238a(6) =652a(7) =1692a(8) =4475a(9) =11253a(10) =29070a(11) =71617a(12) =181979a(13) =441975a(14) =1109592a(15) =2666926a(16) =6634665a(17) =15820749a(18) =39080590a(19) =92613969a(20) =227491759a(21) =536439166a(22) =1311671628a(23) =3080422550a(24) =7503699723a(25) =17562474756a(26) =42645714258