A210887 -id:A210887 - cp's OEIS frontend

A210886 Dates after Jan 01 1000 in chronological order which are palindromic when they are written in the format DDMMYYYY. Leading zeros of the terms are suppressed.

10011001, 20011002, 30011003, 1011010, 11011011, 21011012, 31011013, 2011020, 12011021, 22011022, 3011030, 13011031, 23011032, 4011040, 14011041, 24011042, 5011050, 15011051, 25011052, 6011060, 16011061, 26011062, 7011070, 17011071, 27011072, 8011080, 18011081, 28011082, 9011090, 19011091

Offset: 1

Hieronymus Fischer, Apr 01 2012

There are exactly 335 such palindromic dates between Jan 1 1000 and Dec 31 9999 (see b-file for the complete list).
See A210885 for the number of days after 'Jan 1 1000' to get such a palindromic date.
The first palindromic dates after 'Jan 01 2000' are 10022001, 20022002, 1022010, 11022011, 21022012, 2022020, 12022021, 22022022, 3022030, 13022031, 23022032, 4022040, 14022041, 24022042, 5022050, ... which are the 62nd, 63rd, ... 76th ... dates of the original sequence.

			The first palindromic date in DDMMYYYY format after 'Jan 01 1000' is a(1)=10011001 (= 'Jan 10 1001' = 'Jan 01 1000' + A210885(1) days);
The fourth palindromic date in DDMMYYYY format after 'Jan 01 1000' is a(4)=1011010=01011010 (= 'Jan 01 1010' = 'Jan 01 1000' + A210885(4) days);
The 66th palindromic date in DDMMYYYY format after 'Jan 01 1000' is a(66)=21022012 (= 'Feb 21 2012' = 'Jan 01 1000' + A210885(66) days)
The last (335th) palindromic date in DDMMYYYY format before the year 10000 is a(335)=29099092 (= 'Sep 29 9092' = 'Jan 01 1000' + A210885(335) days).

Hieronymus Fischer, Table of n, a(n) for n = 1..335

Cf. A210883 - A210885, A210887 - A210895, A106605, A107273, A107275.

a(n)=DDMMYYYY_date('Jan 1 1000' + A210885(n)).

n-th date after 'Jan 1 2000' = a(61+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.

Original entry on oeis.org

101101, 201102, 301103, 11110, 111111, 211112, 21120, 121121, 221122, 31130, 131131, 231132, 41140, 141141, 241142, 51150, 151151, 251152, 61160, 161161, 261162, 71170, 171171, 271172, 81180, 181181, 281182, 91190, 191191, 291192

Offset: 1

Hieronymus Fischer, Apr 01 2012

There are exactly 30 such palindromic dates between Jan 1 00 and Dec 31 99 (see b-file for the complete list).

See A210887 for the number of days after 'Mar 1 00' to get such a palindromic date.

			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);
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).
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).

Hieronymus Fischer, Table of n, a(n) for n = 1..30
Index entries for linear recurrences with constant coefficients, signature (1,0,1,-1).

Cf. A210883 - A210887, A210889 - A210895, A106605, A107273, A107275

a(n) = DDMMYY_date('Mar 1 00' + A210887(n)).
From Chai Wah Wu, Feb 03 2021: (Start)
a(n) = a(n-1) + a(n-3) - a(n-4) for n > 7.
G.f.: x*(100001*x^6 - 391094*x^3 + 100001*x^2 + 100001*x + 101101)/(x^4 - x^3 - x + 1). (End)

cp's OEIS Frontend

A210886 Dates after Jan 01 1000 in chronological order which are palindromic when they are written in the format DDMMYYYY. Leading zeros of the terms are suppressed.

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