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 A085436 #3 Mar 30 2012 18:37:43 %S A085436 1,0,1,1,5,2,13,8,21,17,54,31,99,70,139,131,295,207,488,387,698,657, %T A085436 1253,995,1923,1707,2785,2670,4563,3900,6840,6287,9606,9445,14746, %U A085436 13517,21635,20614,30000,29903,44581,42067,63259 %N A085436 Number of partitions of n without rotational symmetry (or 1-fold symmetry). %C A085436 A partition of n is considered to have d-fold symmetry if it consists of runs of (one or more) equal integers that add up to d or a multiple of n/d. %C A085436 Set partitions with rotational d-fold symmetry (A084423) have block lengths that are d-fold symmetrical partitions of n, (d|n), as defined above. %e A085436 a(6)=2 since the 11 partitions of 6 consist of 4 having 6-fold symmetry: {6},{3,3},{2,2,2},{1,1,1,1,1,1}; 1 with 3-fold: {3,1,1,1}; 4 with 2-fold: {4,2},{4,1,1},{2,2,1,1},{2,1,1,1,1}; and only 2 with 1-fold symmetry (= no rotational symmetry): {5,1} and {3,2,1}. %t A085436 Needs["DiscreteMath`Combinatorica`"]; f := Function[{n, d}, Cases[ Partitions[n], q_List /; (Union[ Mod[ (First[ # ] Length[ # ] &) /@ Split[q], d]] == {0})]]; fixp[j_] := Table[d = Part[ Divisors[n], k]; Length@f[n, d], {n, j}, {k, DivisorSigma[0, n]}]; Do[ Print[ Last[ Table[ Fold[ Plus, 0, MoebiusMu[ n/ Divisors[n]] Reverse[ fixp[i][[i]] ]], {n, i}]]], {i, 1, 43}] %Y A085436 Cf. A084423. %K A085436 nonn %O A085436 1,5 %A A085436 _Wouter Meeussen_, Aug 14 2003 %E A085436 Edited and extended by _Robert G. Wilson v_, Aug 15 2003