Number of n-bead necklaces with 2 colors when turning over is not allowed; also number of output sequences from a simple n-stage cycling shift register; also number of binary irreducible polynomials whose degree divides n.
A000031
Number of n-bead necklaces with 2 colors when turning over is not allowed; also number of output sequences from a simple n-stage cycling shift register; also number of binary irreducible polynomials whose degree divides n.
Terms
- a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =8a(6) =14a(7) =20a(8) =36a(9) =60a(10) =108a(11) =188a(12) =352a(13) =632a(14) =1182a(15) =2192a(16) =4116a(17) =7712a(18) =14602a(19) =27596a(20) =52488a(21) =99880a(22) =190746a(23) =364724a(24) =699252a(25) =1342184a(26) =2581428a(27) =4971068a(28) =9587580a(29) =18512792
External references
- oeis: A000031