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 A194742 #5 Mar 30 2012 18:57:44 %S A194742 1,2,3,4,1,3,5,7,1,4,7,10,1,5,9,13,1,6,11,16,21,5,11,17,23,4,11,18,25, %T A194742 3,11,19,27,2,11,20,29,38,9,19,29,39,7,18,29,40,5,17,29,41,3,16,29,42, %U A194742 55,13,27,41,55,10,25,40,55,7,23,39,55,4,21,38,55,72,17,35,53 %N A194742 Number of k such that {k*sqrt(5)} < {n*sqrt(5)}, where { } = fractional part. %t A194742 r = Sqrt[5]; p[x_] := FractionalPart[x]; %t A194742 u[n_, k_] := If[p[k*r] <= p[n*r], 1, 0] %t A194742 v[n_, k_] := If[p[k*r] > p[n*r], 1, 0] %t A194742 s[n_] := Sum[u[n, k], {k, 1, n}] %t A194742 t[n_] := Sum[v[n, k], {k, 1, n}] %t A194742 Table[s[n], {n, 1, 100}] (* A194742 *) %t A194742 Table[t[n], {n, 1, 100}] (* A194743 *) %Y A194742 Cf. A194743, A194738. %K A194742 nonn %O A194742 1,2 %A A194742 _Clark Kimberling_, Sep 02 2011