A107276 Vertically symmetrical dates DDMMYY ("condensed European notation") considered as numbers, in increasing order.

101101, 111111, 121151, 151121, 181181, 201105, 211115, 221155, 251125, 281185

Offset: 1

Author

Alexandre Wajnberg, May 19 2005

Keywords

• base
• easy
• fini
• full
• nonn

Comments

2 and 5 are taken as mirror images (as on calculator displays). From now on, the next symmetric date is November 20 2005 (201105). a(1)=101101, a(2)=111111 and a(5)=181181 share the property to present also two symmetrical halves. Next one is November 11 2011 (11 11 11).

Next one is Nov 21 2015 (211115). - M. F. Hasler, Feb 27 2013

Crossrefs

Cf. A053701, A106605.

Programs

PARI

A107276(n)=101101+[8008,0,1001,2005,5002][n%5+1]*10+n\6*100004 \\ M. F. Hasler, Feb 28 2013

Extensions

Edited by Jon E. Schoenfield, Feb 10 2015