A048344 a(n) * a(n)_reversed is a palindrome (and a(n) is not palindromic).

12, 21, 102, 112, 122, 201, 211, 221, 1002, 1011, 1012, 1021, 1022, 1101, 1102, 1112, 1121, 1201, 1202, 1211, 2001, 2011, 2012, 2021, 2101, 2102, 2111, 2201, 10002, 10011, 10012, 10021, 10022, 10102, 10111, 10112, 10121, 10202, 10211, 11001

Offset

1,1

Comments

Does any term in this sequence have any digit greater than 2? [From Harvey P. Dale, Nov 05 2011]

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

P. De Geest, Palindromic Products of Non Palindromic Integers and their Reversals

Example

E.g. 10021 x 12001 = 120262021 is a palindrome.

Mathematica

palQ[n_]:=Module[{idn=IntegerDigits[n], ridn, idn2}, ridn=Reverse[idn]; idn2 = IntegerDigits[ n FromDigits[ridn]]; idn!=ridn&&idn2==Reverse[idn2]]; Select[ Range[11100], palQ] (* Harvey P. Dale, Nov 05 2011 *)
Select[Range[12000], !PalindromeQ[#]&&PalindromeQ[# IntegerReverse[#]]&] (* Harvey P. Dale, Jul 10 2023 *)

Prog

(Haskell)
a048344 n = a048344_list !! (n-1)
a048344_list = filter f a029742_list where
   f x = a136522 (x * a004086 x) == 1
-- Reinhard Zumkeller, Oct 09 2011
(Python)
A048344_list = []
for n in range(1, 10**5):
....s = str(n)
....s2 = str(n)[::-1]
....if s != s2:
........s3 = str(n*int(s2))
........if s3 == s3[::-1]:
............A048344_list.append(n) # Chai Wah Wu, Sep 08 2014

Crossrefs

Cf. A048343.

Cf. A004086, A136522, A029742.

Sequence in context: A228766 A157157 A218043 * A039402 A043225 A111066

Adjacent sequences: A048341 A048342 A048343 * A048345 A048346 A048347

Keyword

nonn,base,nice

Author

Patrick De Geest, Feb 15 1999

Extensions

Offset corrected by Reinhard Zumkeller, Oct 09 2011

Status

approved