A210893 - OEIS

%I #10 Apr 16 2014 00:28:19

%S 10011001,1011010,11011011,2011020,12011021,3011030,4011040,5011050,

%T 6011060,7011070,8011080,9011090,10111101,1111110,11111111,2111120,

%U 12111121,3111130,4111140,5111150,6111160,7111170,8111180,9111190,10211201,1211210,11211211,2211220,12211221

%N Dates after Jan 01 1000 in chronological order which are palindromic when they are written according to the format MMDDYYYY (American standard). Leading zeros of the terms are suppressed.

%C There are exactly 331 such palindromic dates between Jan 1 1000 and Dec 31 9999 (see b-file for the complete list).

%C Dates palindromic in the MMDDYYYY format are also palindromic in the YYYYMMDD format. Consequently, this sequence represents the same dates as A210884.

%C See A210883 for the number of days after Jan 1 1000 to get such a palindromic date.

%C The first such palindromic dates after Jan 01 2000 are 10022001, 1022010, 11022011, 2022020, 12022021, 3022030, 4022040, 5022050, 6022060, 7022070, 8022080, 9022090, 10122101, which are the 44th, 45th, ... 56th ... dates of the original sequence.

%H Hieronymus Fischer, <a href="/A210893/b210893.txt">Table of n, a(n) for n = 1..331</a>

%F a(n)=MMDDYYYY_date('Jan 1 1000' + A210883(n)).

%F n-th date after 'Jan 1 2000' = a(43+n).

%e The first palindromic date in MMDDYYYY format after 'Jan 01 1000' is a(1)=10011001 (= 'Oct 01 1001' = 'Jan 01 1000' + A210893(1) days);

%e The second palindromic date in MMDDYYYY format after 'Jan 01 1000' is a(2)=1011010=01011010 (= 'Jan 01 1010' = 'Jan 01 1000' + A210893(2) days);

%e The 47th palindromic date in MMDDYYYY format after 'Jan 01 1000' is a(47)=2022020=02022020 (= 'Feb 02 2020' = 'Jan 01 1000' + A210893(47) days).

%e The last (331st) palindromic date in MMDDYYYY format before the year 10000 is a(331)=9299290=09299290 (= 'Sep 29 9290' = 'Jan 01 1000' + A210893(331) days).

%Y Cf. A210883 - A210892, A210894 - A210895, A106605, A107273, A107275.

%K nonn,base

%O 1,1

%A _Hieronymus Fischer_, Apr 01 2012