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A107273
Vertically symmetrical dates MMDDYYYY (American notation) excluding years which are divisible by 10, considered as numbers, in increasing order.
16
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).
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.
Sequence in context: A173002 A139120 A210893 * A106605 A210884 A107275
KEYWORD
base,easy,fini,full,nonn
AUTHOR
Alexandre Wajnberg, May 19 2005
EXTENSIONS
Definition clarified by Hieronymus Fischer, Apr 01 2012
STATUS
approved