Number of monic irreducible polynomials over GF(4) of degree <= n.

Terms

a(0) =4a(1) =10a(2) =30a(3) =90a(4) =294a(5) =964a(6) =3304a(7) =11464a(8) =40584a(9) =145338a(10) =526638a(11) =1924378a(12) =7086598a(13) =26259388a(14) =97842104a(15) =366273464a(16) =1376854004a(17) =5194587924a(18) =19661846184a(19) =74637375132a(20) =284068160592