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A172293 a(n) = number of prime knots with determinant 2n+1 and signature 0. 9

%I

%S 1,0,1,0,3,0,2,0,2,0,1,0,2,0,2,0,0,0,2,0,1,0,3,0,2,0,1,0,0,0,1

%N a(n) = number of prime knots with determinant 2n+1 and signature 0.

%D Peter R. Cromwell, Knots and Links, Cambridge University Press, 2004. See p. 146, Fig. 6.6.

%e a(0) = 1 because the only prime knot with determinant 2*0+1=1 and s=0 is 0_1, the unknot.

%e a(2) = 1 because the only prime knot with determinant 2*2+1=5 and s=0 is 4_1, the figure-8 knot.

%e a(4) = 3 because the three prime knot with determinant 2*4+1=9 and s=0 are 6_1, 8_20, and 9_46.

%Y Cf. A002863.

%Y First column of A172184.

%K nonn,more

%O 0,5

%A _Jonathan Vos Post_, Nov 20 2010

%E Partially edited by _N. J. A. Sloane_, Jun 10 2019

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Last modified September 20 02:19 EDT 2021. Contains 347577 sequences. (Running on oeis4.)