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 A249604 #20 Jun 26 2017 07:29:26
%S A249604 1,11,211,3211,53211,853211,13853211,223853211,3623853211,58623853211,
%T A249604 948623853211,15348623853211,248348623853211,4018348623853211,
%U A249604 65018348623853211,1052018348623853211,17022018348623853211,275422018348623853211,4456422018348623853211
%N A249604 a(n) = Sum_{i=1..n} Fibonacci(i)*10^(i-1).
%D A249604 D. R. Kaprekar, Demlofication of Fibonacci numbers, Journal of University of Bombay, Nov. 1945. Reprinted in D. R. Kaprekar, Demlo Numbers, Privately printed, Khare's Wada, Deolali, India, 1948, pp. 75-82.
%H A249604 Colin Barker, <a href="/A249604/b249604.txt">Table of n, a(n) for n = 1..800</a>
%H A249604 <a href="/index/Rec#order_03">Index entries for linear recurrences with constant coefficients</a>, signature (11,90,-100).
%F A249604 O.g.f.: x/((1-x)*(1-10*x-100*x^2)). - _Bruno Berselli_, Nov 04 2014
%F A249604 From _Colin Barker_, Jun 26 2017: (Start)
%F A249604 a(n) = ((-10 + (5-21*sqrt(5))*(5-5*sqrt(5))^n + (5*(1+sqrt(5)))^n*(5+21*sqrt(5)))) / 1090.
%F A249604 a(n) = 11*a(n-1) + 90*a(n-2) - 100*a(n-3) for n>3.
%F A249604 (End)
%e A249604 To get a(10), for example:
%e A249604 ..........1
%e A249604 .........1
%e A249604 ........2
%e A249604 .......3
%e A249604 ......5
%e A249604 .....8
%e A249604 ...13
%e A249604 ..21
%e A249604 .34
%e A249604 55
%e A249604 -----------
%e A249604 58623853211
%o A249604 (PARI) Vec(x / ((1-x)*(1-10*x-100*x^2)) + O(x^30)) \\ _Colin Barker_, Jun 26 2017
%Y A249604 Cf. A000045, A000071.
%Y A249604 The analog for powers of 2 is A064108.
%K A249604 nonn,easy
%O A249604 1,2
%A A249604 _N. J. A. Sloane_, Nov 04 2014