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Number of irreducible indecomposable bicolored immersions of unoriented circle into oriented sphere with n double points.
1

%I #10 Jun 09 2024 09:04:04

%S 0,0,2,1,4,6,24,73,322,1274

%N Number of irreducible indecomposable bicolored immersions of unoriented circle into oriented sphere with n double points.

%H Robert Coquereaux and Jean-Bernard Zuber, <a href="https://doi.org/10.1142/S0218216516500474">Maps, immersions and permutations</a>, Journal of Knot Theory and Its Ramifications, Vol. 25, No. 8 (2016), 1650047; <a href="https://arxiv.org/abs/1507.03163">arXiv preprint</a>, arXiv:1507.03163 [math.CO], 2015-2016. See Table 7.

%F a(2*n) = A264761(2*n), a(2*n+1) = 2 * A264760(2*n+1). - _Andrey Zabolotskiy_, Jun 05 2024

%Y Cf. A264760, A264761, A268561, A268572.

%K nonn,more

%O 1,3

%A _N. J. A. Sloane_, Mar 03 2016

%E Name clarified by _Andrey Zabolotskiy_, Jun 08 2024