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A210887 Number of days after Mar 01 00 such that the date written in the format DD.MM.YY is palindromic. 3
619, 994, 1369, 3897, 4272, 4648, 7551, 7926, 8301, 11204, 11579, 11955, 14858, 15233, 15608, 18511, 18886, 19262, 22165, 22540, 22915, 25818, 26193, 26569, 29472, 29847, 30222, 33125, 33500, 33876 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
There are exactly 30 such palindromic dates between Jan 01 00 and Dec 31 99 (see b-file for the complete list).
See A210888 for the corresponding dates.
The reference date Mar 01 00 makes sense, since this result in a sequence which is independent from the leap year / non-leap year property of the reference year "00".
LINKS
Hieronymus Fischer, Table of n, a(n) for n = 1..30
FORMULA
From Chai Wah Wu, Feb 03 2021: (Start)
a(n) = a(n-1) + a(n-6) - a(n-7) for n > 10.
G.f.: x*(375*x^9 + 2284*x^6 + 376*x^5 + 375*x^4 + 2528*x^3 + 375*x^2 + 375*x + 619)/(x^7 - x^6 - x + 1). (End)
EXAMPLE
The first palindromic date in DD.MM.YY format after "Jan 01 00" is A210888(1)=101101 (="10.11.01"= "Nov 10 01" = "Mar 01 00" + 619 days);
The sixth palindromic date in DD.MM.YY format after "Jan 01 00" is A210888(6)=211112 (="21.11.12"= "Nov 21 12" = "Mar 01 00" + 4648 days).
The last (30th) palindromic date in DD.MM.YY format after "Jan 01 00" is A210888(30)=291192 (="29.11.92"= "Nov 29 92" = "Mar 01 00" + 33876 days).
CROSSREFS
Sequence in context: A234559 A251323 A020377 * A118467 A200812 A133207
KEYWORD
nonn,base
AUTHOR
Hieronymus Fischer, Apr 01 2012
STATUS
approved

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Last modified June 25 13:13 EDT 2024. Contains 373705 sequences. (Running on oeis4.)