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 A077597 #22 Jun 09 2015 15:59:52
%S A077597 0,2,4,7,9,13,15,19,22,26,28,34,36,40,44,49,51,57,59,65,69,73,75,83,
%T A077597 86,90,94,100,102,110,112,118,122,126,130,139,141,145,149,157,159,167,
%U A077597 169,175,181,185,187,197,200,206,210,216,218,226,230,238,242,246,248,260
%N A077597 Coefficient of x in the n-th Moebius polynomial (A074586), M(n,x), which satisfies M(n,-1)=mu(n) the Moebius function of n.
%C A077597 This is also the number of ways to misidentify a solar mode of degree l with modes of lower degree. See paper with Lou Lanzerotti (in preparation). - David J. Thomson, Oct 28 2010
%H A077597 R. K. Guy, <a href="http://www.jstor.org/stable/2690263">Conway's prime producing machine</a>, Math. Mag. 56 (1983), no. 1, 26-33 (see p. 33).
%F A077597 a(n) = Sum_{k = 1..n} floor((n+1)/k). - _N. J. A. Sloane_, Oct 28 2008
%F A077597 Since a(n) = A006218(n+1) - 1, asymptotics and bounds may be obtained from that entry.
%e A077597 These are the coefficients of x in the Moebius polynomials, which begin: M(1,x) = 1; M(2,x) = 1 + 2x; M(3,x) = 1 + 4x + 2x^2; M(4,x) = 1 + 7x + 8x^2 + 2x^3; M(5,x) = 1 + 9x + 15x^2 + 10x^3 + 2x^4; M(6,x) = 1 + 13x + 30x^2 + 27x^3 + 12x^4 + 2x^5; M(7,x) = 1 + 15x + 43x^2 + 57x^3 + 39x^4 + 14x^5 + 2x^6; M(8,x) = 1 + 19x + 67x^2 + 108x^3 + 98x^4 + 53x^5 + 16x^6 + 2x^7.
%t A077597 a[n_] := Sum[ Floor[(n+1)/k], {k, 1, n+1}] - 1; Table[a[n], {n, 0, 59}] (* _Jean-François Alcover_, Jun 18 2013 *)
%Y A077597 Cf. A074586, A074587, A077596, A077598, A077599, A077600, A077601, A085683.
%Y A077597 Equals A006218(n+1) - 1.
%K A077597 nonn
%O A077597 0,2
%A A077597 _Benoit Cloitre_ and _Paul D. Hanna_, Nov 10 2002