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

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