%I #12 Jan 21 2021 10:25:45
%S 1,21,273,4161,22517,28347,65793,69905,81913,87381,106483,109483,
%T 121143,292721,299593,317273,319449,350933,354101,368589,378653,
%U 421811,470951,479831,1049601,1135953,1171313,1172721,1208009,1257113,1269593,1295481,1332549,1371877
%N Numbers that are both binary palindromes and binary Niven numbers.
%H Amiram Eldar, <a href="/A334529/b334529.txt">Table of n, a(n) for n = 1..10000</a>
%e 21 is a term since its binary representation, 10101, is palindromic, and 1 + 0 + 1 + 0 + 1 = 3 is a divisor of 21.
%t Select[Range[10^6], PalindromeQ[(d = IntegerDigits[#, 2])] && Divisible[#, Plus @@ d] &]
%o (Python)
%o def ok(n): b = bin(n)[2:]; return b==b[::-1] and n%sum(map(int, b)) == 0
%o def aupto(nn): return [m for m in range(1, nn+1) if ok(m)]
%o print(aupto(1371877)) # _Michael S. Branicky_, Jan 21 2021
%Y Intersection of A006995 and A049445.
%Y Cf. A082232.
%K nonn,base
%O 1,2
%A _Amiram Eldar_, May 05 2020