Number of M-sequences m_0,...,m_4 with m_1 < n.

Terms

a(0) =2a(1) =6a(2) =32a(3) =203a(4) =1144a(5) =5345a(6) =20926a(7) =70506a(8) =209746a(9) =562727a(10) =1384758a(11) =3167606a(12) =6807620a(13) =13863904a(14) =26941700a(15) =50245591a(16) =90358146a(17) =157312324a(18) =266040452a(19) =438299013a(20) =705186944a(21) =1110395771a(22) =1714352818a(23) =2599444040a(24) =3876530866