cp's OEIS Frontend

A210888 Dates after Jan 01 00 in chronological order which are palindromic when they are written in the format DD.MM.YY. The terms are listed as numbers (without the dots). Leading zeros of the terms are suppressed.

%I A210888 #17 Feb 03 2021 21:54:58
%S A210888 101101,201102,301103,11110,111111,211112,21120,121121,221122,31130,
%T A210888 131131,231132,41140,141141,241142,51150,151151,251152,61160,161161,
%U A210888 261162,71170,171171,271172,81180,181181,281182,91190,191191,291192
%N A210888 Dates after Jan 01 00 in chronological order which are palindromic when they are written in the format DD.MM.YY. The terms are listed as numbers (without the dots). Leading zeros of the terms are suppressed.
%C A210888 There are exactly 30 such palindromic dates between Jan 1 00 and Dec 31 99 (see b-file for the complete list).
%C A210888 See A210887 for the number of days after 'Mar 1 00' to get such a palindromic date.
%H A210888 Hieronymus Fischer, <a href="/A210888/b210888.txt">Table of n, a(n) for n = 1..30</a>
%H A210888 <a href="/index/Rec#order_04">Index entries for linear recurrences with constant coefficients</a>, signature (1,0,1,-1).
%F A210888 a(n) = DDMMYY_date('Mar 1 00' + A210887(n)).
%F A210888 From _Chai Wah Wu_, Feb 03 2021: (Start)
%F A210888 a(n) = a(n-1) + a(n-3) - a(n-4) for n > 7.
%F A210888 G.f.: x*(100001*x^6 - 391094*x^3 + 100001*x^2 + 100001*x + 101101)/(x^4 - x^3 - x + 1). (End)
%e A210888 The first palindromic date in DD.MM.YY format after 'Jan 01 00' is a(1)=101101 (='10.11.01' = 'Nov 10 01' = 'Mar 01 00' + A210887(1) days);
%e A210888 The sixth palindromic date in DD.MM.YY format after 'Jan 01 00' is a(6)=211112 (='21.11.12' = 'Nov 21 12' = 'Mar 01 00' + A210887(6) days).
%e A210888 The last (30th) palindromic date in DD.MM.YY format after 'Jan 01 00' is a(30)=291192 (='29.11.92' = 'Nov 29 92' = 'Mar 01 00' + A210887(30) days).
%Y A210888 Cf. A210883 - A210887,  A210889 - A210895, A106605, A107273, A107275
%K A210888 nonn,base
%O A210888 1,1
%A A210888 _Hieronymus Fischer_, Apr 01 2012