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 A106030 #9 Dec 14 2019 21:33:09 %S A106030 1,2,1,2,2,2,2,1,2,4,1,2,2,2,2,2,1,4,2,2,3,4,1,2,4,1,4,2,2,2,4,1,4,2, %T A106030 2,2,1,2,2,4,2,2,4,2,1,2,2,4,4,3,2,2,2,4,1,4,2,2,4,1 %N A106030 a(n) is the number of orbits under the action of GL_2[Z] on the primitive binary quadratic forms of discriminant D, where D=m if m=1 (mod 4), D=4*m otherwise and m>1 is the n-th squarefree number. %C A106030 A104888 is the same except it is under the action of SL_2[Z]. %H A106030 S. R. Finch, <a href="http://www.people.fas.harvard.edu/~sfinch/">Class number theory</a> %H A106030 Steven R. Finch, <a href="/A000924/a000924.pdf">Class number theory</a> [Cached copy, with permission of the author] %H A106030 Jens Jonasson, <a href="http://www.mai.liu.se/~jejon/">Classes of integral binary quadratic forms</a>, Master's thesis (2001), Appendix B. %e A106030 m = 2, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, ... %e A106030 with corresponding discriminant %e A106030 D = 8, 12, 5, 24, 28, 40, 44, 13, 56, 60, 17, .... %Y A106030 Cf. A104888. %K A106030 nonn %O A106030 1,2 %A A106030 _Steven Finch_, May 05 2005