cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A319598 Numbers in base 10 that are palindromic in bases 2, 4, 8, and 16.

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%I A319598 #32 Jun 24 2019 16:47:43
%S A319598 0,1,3,5,4095,4097,12291,20485,21845,16777215,16777217,16781313,
%T A319598 50331651,50343939,83886085,83906565,89458005,89478485,68702703615,
%U A319598 68719476735,68719476737,68736258049,206158430211,206208774147,343597383685,343602954245,343681290245
%N A319598 Numbers in base 10 that are palindromic in bases 2, 4, 8, and 16.
%C A319598 Intersection of A006995, A014192, A029803, and A029730.
%C A319598 This sequence is infinite because it contains terms of the forms 4096^k-1 (k>=0) and 4096^k+1 (k>0). - _Bruno Berselli_, Sep 24 2018
%H A319598 A.H.M. Smeets, <a href="/A319598/b319598.txt">Table of n, a(n) for n = 1..114</a> (first 70 terms from Rémy Sigrist)
%e A319598 4095 = 111111111111_2 = 333333_4 = 7777_8 = FFF_16. Hence 4095 is in the sequence.
%t A319598 palQ[n_, b_] := PalindromeQ[IntegerDigits[n, b]];
%t A319598 Reap[Do[If[palQ[n, 2] && palQ[n, 4] && palQ[n, 8] && palQ[n, 16], Print[n]; Sow[n]], {n, 0, 10^6}]][[2, 1]] (* _Jean-François Alcover_, Sep 25 2018 *)
%o A319598 (Sage) [n for n in (0..100000) if Word(n.digits(2)).is_palindrome() and Word(n.digits(4)).is_palindrome() and Word(n.digits(8)).is_palindrome() and Word(n.digits(16)).is_palindrome()]
%Y A319598 Cf. A006995 (base 2), A014192 (base 4), A029803 (base 8), and A029730 (base 16).
%K A319598 nonn,base
%O A319598 1,3
%A A319598 _Jeremias M. Gomes_, Sep 24 2018
%E A319598 a(19)-a(27) from _Rémy Sigrist_, Nov 15 2018