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 A047256 #36 Oct 04 2024 00:25:05
%S A047256 0,1,2,3,5,6,7,8,9,11,12,13,14,15,17,18,19,20,21,23,24,25,26,27,29,30,
%T A047256 31,32,33,35,36,37,38,39,41,42,43,44,45,47,48,49,50,51,53,54,55,56,57,
%U A047256 59,60,61,62,63,65,66,67,68,69,71,72,73,74,75,77,78,79
%N A047256 Numbers that are congruent to {0, 1, 2, 3, 5} mod 6.
%H A047256 <a href="/index/Rec#order_06">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,1,-1).
%F A047256 G.f.: x^2*(1+x)*(x^3 + x^2 + 1) / ( (x^4 + x^3 + x^2 + x + 1)*(x-1)^2 ). - _R. J. Mathar_, Oct 08 2011
%F A047256 Sum_{n>=2} (-1)^n/a(n) = (3-2*sqrt(3))*Pi/36 + log(2+sqrt(3))/sqrt(3). - _Amiram Eldar_, Dec 17 2021
%F A047256 a(n) = n + floor(n/5) - 1. - _Aaron J Grech_, Oct 03 2024
%t A047256 Flatten[# + {0, 1, 2, 3, 5} & /@ (6 Range[0, 11])] (* or *)
%t A047256 Select[Range[0, 67], MemberQ[{0, 1, 2, 3, 5}, Mod[#, 6]] &] (* _Robert G. Wilson v_, Sep 26 2016 *)
%t A047256 LinearRecurrence[{1,0,0,0,1,-1},{0,1,2,3,5,6},60] (* _Harvey P. Dale_, Jul 20 2020 *)
%Y A047256 Cf. A047226.
%K A047256 nonn,easy
%O A047256 1,3
%A A047256 _N. J. A. Sloane_