Number of complete rulers with n segments.

Terms

a(0) =1a(1) =1a(2) =3a(3) =10a(4) =38a(5) =175a(6) =885a(7) =5101a(8) =32080a(9) =219569a(10) =1616882a(11) =12747354a(12) =106948772a(13) =950494868