This site is supported by donations to The OEIS Foundation.

 Please make a donation to keep the OEIS running. We are now in our 55th year. In the past year we added 12000 new sequences and reached 8000 citations (which often say "discovered thanks to the OEIS"). We need to raise money to hire someone to manage submissions, which would reduce the load on our editors and speed up editing. Other ways to donate

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A319583 Numbers in base 10 that are palindromic in bases 2, 4, and 16. 0
 0, 1, 3, 5, 15, 17, 51, 85, 255, 257, 273, 771, 819, 1285, 1365, 3855, 4095, 4097, 4369, 12291, 13107, 20485, 21845, 61455, 65535, 65537, 65793, 69649, 69905, 196611, 197379, 208947, 209715, 327685, 328965, 348245, 349525, 983055, 986895, 1044735, 1048575 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS Intersection of A006995, A014192, and A029730. This sequence is infinite as it contains 15*(1 + 16^k) for any k > 0. - Rémy Sigrist, Sep 23 2018 LINKS EXAMPLE 255 is 11111111 in binary, 3333 in quaternary and FF in hexadecimal. Hence 255 is in the sequence. Although 21 is 10101 in binary and 111 in quaternary, it is 15 in hexadecimal and therefore not in the sequence. MATHEMATICA palQ[n_, b_] := PalindromeQ[IntegerDigits[n, b]]; Reap[Do[If[palQ[n, 2] && palQ[n, 4] && palQ[n, 16], Print[n]; Sow[n]], {n, 0, 10^6}]][[2, 1]] (* Jean-François Alcover, Sep 25 2018 *) PROG (Sage) [n for n in (0..1000) if Word(n.digits(2)).is_palindrome() and Word(n.digits(4)).is_palindrome() and Word(n.digits(16)).is_palindrome()] (MAGMA) [n: n in [0..2*10^7] | Intseq(n, 2) eq Reverse(Intseq(n, 2)) and Intseq(n, 4) eq Reverse(Intseq(n, 4)) and Intseq(n, 16) eq Reverse(Intseq(n, 16))]; // Vincenzo Librandi, Sep 24 2018 CROSSREFS Cf. A006995 (base 2), A014192 (base 4), and A029730 (base 16). Sequence in context: A192794 A293001 A018358 * A094358 A003527 A004729 Adjacent sequences:  A319580 A319581 A319582 * A319584 A319585 A319586 KEYWORD nonn,base AUTHOR Jeremias M. Gomes, Sep 23 2018 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified December 7 00:16 EST 2019. Contains 329812 sequences. (Running on oeis4.)