This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A213182 #27 Feb 12 2015 04:04:25 %S A213182 10100,10101,10102,10103,10104,10105,10106,10107,10108,10109,10110, %T A213182 10111,10112,10113,10114,10115,10116,10117,10118,10119,10120,10121, %U A213182 10122,10123,10124,10125,10126,10127,10128,10129,10130,10131,10132,10133,10134,10135,10136,10137,10138,10139,10140 %N A213182 Numbers which may represent a date in "condensed European notation" DDMMYY. %C A213182 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. %C A213182 The sequence is finite, the largest term is a(36525)=311299. %C A213182 There are 366*25 + 365*75 = 36525 possible dates. - _Giovanni Resta_, Feb 28 2013 %e A213182 a(1)=10100 represents e.g., Jan 01 1900 or Jan 01 2000. %e A213182 a(100)=10199 (for Jan 01 1999) is followed by a(101)=10200 (for Feb 01 2000). %e A213182 a(1200)=11299 (for Dec 01 1999) is followed by a(1201)=20100 (for Jan 02 2000). %e A213182 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. %Y A213182 Cf. A213184; A106605, A107273, A107275; A210883, A210884, A210885. %K A213182 nonn,fini %O A213182 1,1 %A A213182 _M. F. Hasler_, Feb 27 2013