login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Numbers whose binary and maximal Lucas representations are both palindromic.
3

%I #4 Feb 20 2022 21:44:33

%S 0,3,5,17,85,107,219,1161,1365,1619,2047,4097,6141,19801,25027,68961,

%T 91213,134337,1540157,1804859,11877549,37696497,44092437,142710801,

%U 548269377,3387848595,4073444175,8226780335,31029923047,64662095631,67947722943,126590440407,2145176968607

%N Numbers whose binary and maximal Lucas representations are both palindromic.

%H <a href="/index/Pac#palindromes">Index entries for sequences related to palindromes</a>.

%e The first 10 terms are:

%e n a(n) A007088(a(n)) A130311(a(n))

%e ----------------------------------------

%e 1 0 0 0

%e 2 3 11 11

%e 3 5 101 101

%e 4 17 10001 11111

%e 5 85 1010101 101101101

%e 6 107 1101011 111010111

%e 7 219 11011011 10110101101

%e 8 1161 10010001001 11011111111011

%e 9 1365 10101010101 101010101010101

%e 10 1619 11001010011 101111010111101

%t lazy = Select[IntegerDigits[Range[10^6], 2], SequenceCount[#, {0, 0}] == 0 &]; t = Total[# * Reverse @ LucasL[Range[0, Length[#] - 1]]] & /@ lazy; s = FromDigits /@ lazy[[TakeWhile[Flatten[FirstPosition[t, #] & /@ Range[Max[t]]], NumberQ]]]; Join[{0}, Select[Position[s, _?PalindromeQ] // Flatten, PalindromeQ[IntegerDigits[#, 2]] &]]

%Y Intersection of A006995 and A351717.

%Y Cf. A007088, A130310, A351713.

%K nonn,base

%O 1,2

%A _Amiram Eldar_, Feb 17 2022