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 A047421 #19 Mar 06 2016 08:44:23
%S A047421 0,1,2,3,4,5,6,8,9,10,11,12,13,14,16,17,18,19,20,21,22,24,25,26,27,28,
%T A047421 29,30,32,33,34,35,36,37,38,40,41,42,43,44,45,46,48,49,50,51,52,53,54,
%U A047421 56,57,58,59,60,61,62,64,65,66,67,68,69,70,72,73,74,75
%N A047421 Floor(8n/7).
%C A047421 Up to the offset identical to A004777, cf formula. - _M. F. Hasler_, Oct 06 2014
%H A047421 <a href="/index/Rec#order_08">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,0,0,0,0,1,-1).
%F A047421 a(n) = A004777(n+1). - _M. F. Hasler_, Oct 06 2014
%F A047421 G.f.: x*(1 + x + x^2 + x^3 + x^4 + x^5 + 2*x^6) / (1 - x - x^7 + x^8). [_Bruno Berselli_, Oct 06 2014]
%F A047421 a(n) = n + floor(n/7) = a(n-1) + a(n-7) - a(n-8). [_Bruno Berselli_, Oct 06 2014]
%t A047421 Table[Floor[8 n/7], {n, 0, 80}] (* _Bruno Berselli_, Oct 06 2014 *)
%t A047421 LinearRecurrence[{1,0,0,0,0,0,1,-1},{0,1,2,3,4,5,6,8},70] (* _Harvey P. Dale_, Mar 06 2016 *)
%o A047421 (PARI) a(n)=n\7+n \\ _M. F. Hasler_, Oct 06 2014
%Y A047421 Cf. A032766, A004773, A001068, A047226, A047368, A004777.
%K A047421 nonn,easy
%O A047421 0,3
%A A047421 _N. J. A. Sloane_
%E A047421 More terms from _Ray Chandler_, Sep 05 2004
%E A047421 Restored to version of early 2008 by _M. F. Hasler_, Oct 06 2014