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A062687 Numbers all of whose divisors are palindromic.

%I A062687 #34 Nov 24 2019 06:45:32
%S A062687 1,2,3,4,5,6,7,8,9,11,22,33,44,55,66,77,88,99,101,121,131,151,181,191,
%T A062687 202,242,262,303,313,353,363,373,383,393,404,484,505,606,626,707,727,
%U A062687 757,787,797,808,909,919,929,939,1111,1331,1441,1661,1991,2222,2662
%N A062687 Numbers all of whose divisors are palindromic.
%H A062687 Amiram Eldar, <a href="/A062687/b062687.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..221 from Indranil Ghosh)
%e A062687 The divisors of 44 are 1, 2, 4, 11, 22 and 44, which are all palindromes, so 44 is in the sequence.
%e A062687 808 has divisors are 1, 2, 4, 8, 101, 202, 404, 808, so 808 is in the sequence.
%e A062687 818 is palindromic, but since it's 2 * 409, it's not in the sequence.
%p A062687 isA062687 := proc(n)
%p A062687     for d in numtheory[divisors](n) do
%p A062687         if not isA002113(d) then
%p A062687             return false;
%p A062687         end if;
%p A062687     end do;
%p A062687     true ;
%p A062687 end proc: # _R. J. Mathar_, Sep 09 2015
%t A062687 palQ[n_] := Module[{idn = IntegerDigits[n]}, idn == Reverse[idn]]; Select[Range[2750], And@@palQ/@Divisors[#] &] (* _Harvey P. Dale_, Feb 27 2012 *)
%o A062687 (PARI) isok(n) = {d = divisors(n); rd = vector(#d, i, subst(Polrev(digits(d[i])), x, 10)); (d == rd);} \\ _Michel Marcus_, Oct 10 2014
%Y A062687 Cf. A087991, A084325, A002385 (subset).
%Y A062687 Subsequence of A002113.
%K A062687 base,easy,nonn
%O A062687 1,2
%A A062687 _Erich Friedman_, Jul 04 2001