This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A172441 #12 Apr 30 2024 01:56:11 %S A172441 0,1,0,2,0,2,0,3,0,2,0,4,0,5,0,2,0,2,0,2,0,2,0,2,0,2,0,2,0,1,0,0,0,0, %T A172441 0,0,0,1 %N A172441 Number of prime knots up to nine crossings with determinant 2n+1 and signature 2. %C A172441 Adapted from Figure 6.6. The prime knots up to nine crossings separated by signature and determinant, p. 146, Cromwell. Second column of A172184. %D A172441 Peter R. Cromwell, Knots and Links, Cambridge University Press, 2004. %e A172441 a(1) = 1 because the only prime knot with no more than 9 crossings with determinant 2*1+1=3 and s=2 is 3_1, the left-handed trefoil. %e A172441 a(3) = 2 because the only prime knots with no more than 9 crossings with determinant 2*3+1=7 and s=2 are 5_2 and 9_42. %Y A172441 Cf. A002863, A172184, A172293. %K A172441 nonn,fini,full %O A172441 0,4 %A A172441 _Jonathan Vos Post_, Nov 20 2010 %E A172441 Edited by _Andrey Zabolotskiy_, Apr 29 2024