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A229129
Digital clock palindromic semiprimes.
0
4, 6, 9, 22, 33, 55, 111, 121, 141, 202, 303, 323, 505, 515, 535, 545, 626, 707, 717, 737, 939, 949, 959, 1111, 1441
OFFSET
1,1
COMMENTS
Palindromic semiprimes possible on a 24-hour digital clock, with no seconds. This is similar to A229107 as semiprimes (A001358) are to prime A000040, except this sequence has no seconds.
FORMULA
Digital clock semiprimes (A129336) INTERSECTION Palindromes in base 10 (A002113).
CROSSREFS
KEYWORD
nonn,base,fini,full
AUTHOR
Jonathan Vos Post, Sep 14 2013
STATUS
approved