A213182 Numbers which may represent a date in "condensed European notation" DDMMYY.

10100, 10101, 10102, 10103, 10104, 10105, 10106, 10107, 10108, 10109, 10110, 10111, 10112, 10113, 10114, 10115, 10116, 10117, 10118, 10119, 10120, 10121, 10122, 10123, 10124, 10125, 10126, 10127, 10128, 10129, 10130, 10131, 10132, 10133, 10134, 10135, 10136, 10137, 10138, 10139, 10140

Offset: 1

Author

M. F. Hasler, Feb 27 2013

Keywords

• nonn
• fini

Comments

The "may" in the definition should clarify that, e.g., 290200 is in the sequence since it may represent a date, but not necessarily in any century.

The sequence is finite, the largest term is a(36525)=311299.

There are 366*25 + 365*75 = 36525 possible dates. - Giovanni Resta, Feb 28 2013

Examples

			a(1)=10100 represents e.g., Jan 01 1900 or Jan 01 2000.
a(100)=10199 (for Jan 01 1999) is followed by a(101)=10200 (for Feb 01 2000).
a(1200)=11299 (for Dec 01 1999) is followed by a(1201)=20100 (for Jan 02 2000).
The sequence becomes more interesting after the term 281299, since then the numbers DD02YY drop out for DD > 29 and for DD = 29 depending on YY.
		

Crossrefs

Cf. A213184; A106605, A107273, A107275; A210883, A210884, A210885.