A107273 Vertically symmetrical dates MMDDYYYY (American notation) excluding years which are divisible by 10, considered as numbers, in increasing order.

10011001, 10025001, 10052001, 10088001, 10100101, 10111101, 10125101, 10152101, 10188101, 10200501, 10211501, 10225501, 10252501, 10288501, 11011011, 11025011, 11052011, 11088011, 11100111, 11111111, 11125111

Offset

1,1

Comments

2 and 5 are taken as mirror images (as on calculator displays). a(1)=10011001 and a(20)=11111111 shared the property to present also two symmetrical halves.

This sequence has exactly 42 terms, ending with 12288551 (Dec. 28th 8551).

Links

Iain Fox, Table of n, a(n) for n = 1..42

Prog

(PARI) a(n) = my(d=digits(126+25*((n-1)\14)+(n-1)%14, 5)); fromdigits(apply(i->[0, 1, 2, 5, 8, 5, 2][i+1], concat(d, apply(i->i+3*bitand(i, 2)/2, Vecrev(d))))) \\ Iain Fox, Jul 08 2022

Crossrefs

Condensed American notation dates: A107274.

Metric convention dates: A107275.

Condensed European notation dates: A107276.

Cf. A053701, A106605.

Sequence in context: A173002 A139120 A210893 * A106605 A210884 A107275

Adjacent sequences: A107270 A107271 A107272 * A107274 A107275 A107276

Keyword

base,easy,fini,full,nonn

Author

Alexandre Wajnberg, May 19 2005

Extensions

Definition clarified by Hieronymus Fischer, Apr 01 2012

Status

approved