Binomial transform of A000031.

Terms

a(0) =1a(1) =3a(2) =8a(3) =20a(4) =49a(5) =119a(6) =290a(7) =714a(8) =1781a(9) =4507a(10) =11580a(11) =30208a(12) =79941a(13) =214327a(14) =581292a(15) =1592496a(16) =4400765a(17) =12251895a(18) =34326566a(19) =96694866a(20) =273639617a(21) =777444807a(22) =2216341466a(23) =6336999666a(24) =18165573373a(25) =52191551315a(26) =150254448730a(27) =433350470586