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a(n) is the LCM of palindromic divisors of n.
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%I #16 Mar 27 2020 14:01:28

%S 1,2,3,4,5,6,7,8,9,10,11,12,1,14,15,8,1,18,1,20,21,22,1,24,5,2,9,28,1,

%T 30,1,8,33,2,35,36,1,2,3,40,1,42,1,44,45,2,1,24,7,10,3,4,1,18,55,56,3,

%U 2,1,60,1,2,63,8,5,66,1,4,3,70,1,72,1,2,15,4,77,6,1,40,9,2,1,84,5,2,3,88

%N a(n) is the LCM of palindromic divisors of n.

%C Sequence is not multiplicative. For example, a(141) = 141 != a(3)*a(47) = 3 * 1. - _Franklin T. Adams-Watters_, Oct 27 2006

%H Indranil Ghosh, <a href="/A087999/b087999.txt">Table of n, a(n) for n = 1..50000</a>

%F a(n)=1 for non-palindromic primes like 13.

%e n=252: a(252)=252=n,since palindromic divisors = {1,2,3,4,6,7,9,252};

%e n=255: a(255)=15<n, palind.div ={1,3,5}.

%t Table[LCM @@ Select[Divisors[k], Reverse[x = IntegerDigits[#]] == x &], {k, 88}] (* _Jayanta Basu_, Aug 12 2013 *)

%o (PARI) ispal(x) = my(d=digits(x)); d == Vecrev(d);

%o a(n) = lcm(select(x->ispal(x), divisors(n))); \\ _Michel Marcus_, Mar 27 2020

%Y Cf. A087990.

%K base,nonn

%O 1,2

%A _Labos Elemer_, Oct 14 2003