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 A031982 #25 Jul 02 2025 16:01:56
%S A031982 101,1010101,10101010101,101010101010101,1010101010101010101,
%T A031982 10101010101010101010101,101010101010101010101010101,
%U A031982 1010101010101010101010101010101,10101010101010101010101010101010101,101010101010101010101010101010101010101,1010101010101010101010101010101010101010101
%N A031982 a(n) = 1(01)^(2*n+1).
%D A031982 C. Ashbacher, Problem 514, The Pentagon, Vol. 57, No. 1, Fall 1997, p. 36.
%D A031982 M. Le, On Smarandache Pierce Chain, Smarandache Notions Journal, Vol. 10, No. 1-2-3, 1999, pp. 154-155.
%D A031982 Florentin Smarandache, Properties of the numbers, ASU Special Collections, 1973.
%H A031982 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/SmarandacheSequences.html">Smarandache Sequences</a>.
%H A031982 <a href="/index/Rec#order_02">Index entries for linear recurrences with constant coefficients</a>, signature (10001,-10000).
%F A031982 a(n) = 101*(10^(4*n) - 1)/(10^4 - 1).
%F A031982 From _Elmo R. Oliveira_, Jun 12 2025: (Start)
%F A031982 G.f.: 101/((x-1)*(10000*x-1)).
%F A031982 E.g.f.: 101*exp(x)*(exp(9999*x) - 1)/9999.
%F A031982 a(n) = 10001*a(n-1) - 10000*a(n-2). (End)
%t A031982 101(10^(4Range[10]) - 1)/9999 (* _Alonso del Arte_, May 20 2017 *)
%t A031982 LinearRecurrence[{10001,-10000},{101,1010101},20] (* _Harvey P. Dale_, Aug 18 2019 *)
%o A031982 (PARI) my(x='x+O('x^11)); Vec(101/((1-x)*(1-10000*x))) \\ _Elmo R. Oliveira_, Jun 12 2025
%K A031982 nonn,easy
%O A031982 0,1
%A A031982 J. Castillo (arp(AT)cia-g.com)
%E A031982 More terms from _James Sellers_
%E A031982 a(9)-a(10) from _Elmo R. Oliveira_, Jun 12 2025