Union of the factorial numbers (A000142) and the double factorials of odd numbers (A001147).

A248652

Union of the factorial numbers (A000142) and the double factorials of odd numbers (A001147).

Terms

    a(0) =1a(1) =2a(2) =3a(3) =6a(4) =15a(5) =24a(6) =105a(7) =120a(8) =720a(9) =945a(10) =5040a(11) =10395a(12) =40320a(13) =135135a(14) =362880a(15) =2027025a(16) =3628800a(17) =34459425a(18) =39916800a(19) =479001600a(20) =654729075a(21) =6227020800a(22) =13749310575a(23) =87178291200a(24) =316234143225

External references