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 A118594 Palindromes in base 3 (written in base 3). 12
 0, 1, 2, 11, 22, 101, 111, 121, 202, 212, 222, 1001, 1111, 1221, 2002, 2112, 2222, 10001, 10101, 10201, 11011, 11111, 11211, 12021, 12121, 12221, 20002, 20102, 20202, 21012, 21112, 21212, 22022, 22122, 22222, 100001, 101101, 102201, 110011 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS The number of n-digit terms is given by A225367. - M. F. Hasler, May 05 2013 [Moved here on May 08 2013] Digit-wise application of A000578 (and also superposition of a(n) with its horizontal OR vertical reflection) yields A006072. - M. F. Hasler, May 08 2013 Equivalently, palindromes k (written in base 10) such that 4*k is a palindrome. - Bruno Berselli, Sep 12 2018 LINKS Eric Weisstein's World of Mathematics, Palindromic Number Eric Weisstein's World of Mathematics, Ternary MATHEMATICA (* get NextPalindrome from A029965 *) Select[NestList[NextPalindrome, 0, 1110], Max@IntegerDigits@# < 3 &] (* Robert G. Wilson v, May 09 2006 *) Select[FromDigits/@Tuples[{0, 1, 2}, 8], IntegerDigits[#]==Reverse[ IntegerDigits[ #]]&] (* Harvey P. Dale, Apr 20 2015 *) PROG (PARI) {for(l=1, 5, u=vector((l+1)\2, i, 10^(i-1)+(2*i-11&&i==1, 2]), print1(v*u", ")))} \\ The n-th term could be produced by using (partial sums of) A225367 to skip all shorter terms, and then skipping the adequate number of vectors v until n is reached.  - M. F. Hasler, May 08 2013 (Sage) [int(n.str(base=3)) for n in (0..757) if Word(n.digits(3)).is_palindrome()] # Peter Luschny, Sep 13 2018 CROSSREFS Cf. A007089, A014190, A057148, A118595, A118596, A118597, A118598, A118599, A118600, A002113. Sequence in context: A018711 A018737 A162468 * A263720 A235609 A018351 Adjacent sequences:  A118591 A118592 A118593 * A118595 A118596 A118597 KEYWORD nonn,base,easy AUTHOR Martin Renner, May 08 2006 EXTENSIONS More terms from Robert G. Wilson v, May 09 2006 STATUS approved

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Last modified November 25 11:32 EST 2020. Contains 338623 sequences. (Running on oeis4.)