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A192219
Numbers m such that set of divisors of m is equal to set of reversals of divisors of m but all divisors of m are not palindromic.
0
1226221, 13488431, 123848321, 12467976421, 1030507050301, 1120237320211, 1225559555221, 1234469644321, 1334459544331, 11335577553311, 100330272033001, 101222252222101, 103023070320301, 113143969341311, 121363494363121, 134312696213431
OFFSET
1,1
COMMENTS
All terms are palindromic (subsequence of A002113 - palindromic numbers).
Subsequence of A188650 (numbers that are divisible by all reversals of their divisors).
Union a(n) and A062687 (numbers all of whose divisors are palindromic) is sequence of numbers m such that set of divisors of m is equal to set of reversals of divisors of m: {1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 44, 55, 66, 77, 88, 99, 101, 121, 131, ..., 1226221, ...). - Jaroslav Krizek, Jul 18 2011.
EXAMPLE
1226221 has divisors 1, 1021, 1201, 1226221. Set of divisors is equal to set of reversals of divisors. Divisors 1021 and 1201 are not palindromic.
MATHEMATICA
t = Union[Flatten[Table[d = IntegerDigits[n]; {FromDigits[Join[d, Reverse[d]]], FromDigits[Join[d, Reverse[Most[d]]]]}, {n, 0, 99999}]]]; okQ[n_] := Module[{f = Divisors[n], r}, r = f; Do[r[[i]] = FromDigits[Reverse[IntegerDigits[f[[i]]]]], {i, Length[f]}]; f == Sort[r] && f != r]; Select[t, okQ] (* T. D. Noe, Jul 14 2011 *)
CROSSREFS
Sequence in context: A257159 A254741 A203259 * A282424 A129347 A071146
KEYWORD
nonn,base
AUTHOR
Jaroslav Krizek, Jul 13 2011
EXTENSIONS
a(5)-a(16) (including six found by T. D. Noe) from Donovan Johnson, Jul 14 2011
STATUS
approved