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 A085411 #11 May 05 2025 10:37:28
%S A085411 1,2,7,17,47,102,255,556,1272,2766,6143,13183,28671,61182,131017,
%T A085411 277952,589823,1243800,2621439,5502191,11534073,24111102,50331647,
%U A085411 104843732,218103760,452956158,939522816,1946095599,4026531839,8321365194,17179869183,35433201664
%N A085411 Total number of parts in all compositions of n into relatively prime parts.
%F A085411 Sum_{d|n} mu(n/d)*(d+1)*2^(d-2).
%F A085411 G.f.: Sum_{k>=0} mu(k)*x^k*(1-x^k)/(1-2*x^k)^2.
%F A085411 Equals A054525 * A007318 * [1,2,3,...]. - _Gary W. Adamson_, Jun 11 2007
%F A085411 a(n) = Sum_{k=1..n} k * A101391(n,k). - _Alois P. Heinz_, May 05 2025
%t A085411 f[n_] := Block[{d = Divisors[n]}, (Plus @@ (MoebiusMu[n/d]*(d + 1)*2^(d - 2)))]; Table[ f[n], {n, 1, 30}]
%Y A085411 Cf. A001792, A000740.
%Y A085411 Cf. A007318, A054525, A101391.
%K A085411 easy,nonn
%O A085411 1,2
%A A085411 _Vladeta Jovovic_, Aug 13 2003
%E A085411 More terms from _Robert G. Wilson v_, Aug 15 2003