Euler transform of the swinging factorial A056040.

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =18a(5) =60a(6) =117a(7) =371a(8) =747a(9) =2199a(10) =4697a(11) =12735a(12) =28571a(13) =72815a(14) =169176a(15) =412440a(16) =978086a(17) =2316754a(18) =5547293a(19) =12909723a(20) =30966639a(21) =71357601a(22) =170636159a(23) =391242623a(24) =930120982a(25) =2128073530a(26) =5023630830a(27) =11486060090a(28) =26918052717a(29) =61539213693