|
%I #13 Jun 05 2023 18:54:01
%S 9,15,21,27,33,45,51,63,65,85,93,99,119,129,153,165,189,195,219,231,
%T 255,273,297,325,341,365,381,387,403,427,455,471,495,511,513,561,585,
%U 633,645,693,717,765,771,819,843,891,903,951,975,1023,1025,1057,1105,1137
%N Odd composite integers that are palindromes when written in binary.
%H Robert Israel, <a href="/A163170/b163170.txt">Table of n, a(n) for n = 1..10000</a>
%p rev := proc (n) local nn: nn := convert(n, base, 10): add(nn[j]*10^(nops(nn)-j), j = 1 .. nops(nn)) end proc: a := proc (n) local n2: n2 := convert(n, binary): if 1 < n and `mod`(n, 2) = 1 and isprime(n) = false and rev(n2) = n2 then n else end if end proc: seq(a(n), n = 1 .. 1500); # _Emeric Deutsch_, Jul 24 2009
%Y Cf. A016041.
%K base,nonn
%O 1,1
%A _Leroy Quet_, Jul 22 2009
%E Extended by _Emeric Deutsch_, Jul 24 2009
|
