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A082207 Palindromes whose product of digits is a positive palindrome. 2
1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 22, 33, 111, 121, 131, 141, 151, 161, 171, 181, 191, 212, 222, 313, 676, 777, 1111, 1221, 1331, 2112, 3113, 11111, 11211, 11311, 11411, 11511, 11611, 11711, 11811, 11911, 12121, 12221, 13131, 16761, 17771, 21112, 21212 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

The unary sequence A000042 is a trivial subsequence. Conjecture: There are infinitely many terms in the sequence (of the type 777) for which the product of digits >10.

Subset of A117055, containing terms for which product of digits is greater than 0. - Jayanta Basu, May 15 2013

LINKS

Harvey P. Dale, Table of n, a(n) for n = 1..89 (* All terms up to 10 million. *)

EXAMPLE

777 is a member as 7^3 = 343 is a a palindrome.

MATHEMATICA

id[n_]:=IntegerDigits[n]; palQ[n_]:=Reverse[x=id[n]]==x; t={}; Do[If[palQ[n] && (y=Times@@id[n]) > 0 && palQ[y], AppendTo[t, n]], {n, 21220}]; t (* Jayanta Basu, May 15 2013 *)

Select[Range[22000], FreeQ[IntegerDigits[#], 0]&&AllTrue[{#, Times @@ IntegerDigits[ #]}, PalindromeQ]&] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Nov 22 2019 *)

CROSSREFS

Cf. A082208.

Sequence in context: A239480 A117055 A117056 * A083115 A266280 A250412

Adjacent sequences:  A082204 A082205 A082206 * A082208 A082209 A082210

KEYWORD

base,easy,nonn

AUTHOR

Amarnath Murthy, Apr 10 2003

EXTENSIONS

More terms from Antonio G. Astudillo (afg_astudillo(AT)lycos.com), Apr 19 2003

STATUS

approved

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Last modified July 28 03:49 EDT 2021. Contains 346316 sequences. (Running on oeis4.)