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 A235944 #10 Feb 18 2018 16:26:38
%S A235944 4,1,9,7,4,4,9,4,4,7,9,1,4,1,9,7,4,4,9,4,4,7,9,1,4,1,9,7,4,4,9,4,4,7,
%T A235944 9,1,4,1,9,7,4,4,9,4,4,7,9,1,4,1,9,7,4,4,9,4,4,7,9,1,4,1,9,7,4,4,9,4,
%U A235944 4,7,9,1,4,1,9,7,4,4,9,4,4,7,9,1,4,1,9,7,4,4,9,4,4,7,9,1,4,1,9,7,4,4,9,4,4,7,9,1
%N A235944 Digital roots of squares of Lucas numbers.
%C A235944 The sequence is periodic with period 12.
%H A235944 <a href="/index/Rec#order_12">Index entries for linear recurrences with constant coefficients</a>, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
%F A235944 a(n) = A010888(A001254(n)).
%F A235944 a(n) = a(n-12).
%F A235944 G.f.: -(x^11 +9*x^10 +7*x^9 +4*x^8 +4*x^7 +9*x^6 +4*x^5 +4*x^4 +7*x^3 +9*x^2 +x +4) / (x^12 -1).
%e A235944 a(5)=4 because A000032[5]=11 and the digital root of 11*11 = 121 is 4.
%t A235944 LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1},{4, 1, 9, 7, 4, 4, 9, 4, 4, 7, 9, 1},108] (* _Ray Chandler_, Aug 27 2015 *)
%t A235944 PadRight[{},120,{4,1,9,7,4,4,9,4,4,7,9,1}] (* _Harvey P. Dale_, Feb 18 2018 *)
%o A235944 (PARI)
%o A235944 Vec(-(x^11+9*x^10+7*x^9+4*x^8+4*x^7+9*x^6+4*x^5+4*x^4+7*x^3+9*x^2+x+4)/(x^12-1) + O(x^100))
%Y A235944 Cf. A000032, A001254, A216676.
%K A235944 nonn,easy,base
%O A235944 0,1
%A A235944 _Colin Barker_, Jan 17 2014
%E A235944 Extended by _Ray Chandler_, Aug 27 2015