A136522 a(n) = 1 if n is a palindrome, otherwise 0.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset: 0

Author

N. J. A. Sloane, Apr 21 2008

Keywords

• nonn
• base

Comments

a(A002113(n)) = 1; a(A029742(n)) = 0.

a(n) = A202022(n) for n <= 100, a(101) = 1, A202022(101) = 0. - Reinhard Zumkeller, Dec 10 2011

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
• Index entries for characteristic functions
• Index entries for sequences related to palindromes

Crossrefs

Cf. A002113, A136687, A137180.

Cf. A178225.

Programs

Haskell

a136522 n = fromEnum $ n == a004086 n  -- Reinhard Zumkeller, Apr 08 2011

Mathematica

fQ[n_]:=Module[{id=IntegerDigits[n]}, Boole[id==Reverse[id]]]; Array[fQ, 100] (* Vladimir Joseph Stephan Orlovsky, Dec 29 2010 *)
Table[If[PalindromeQ[n],1,0],{n,0,120}] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, Aug 23 2019 *)

Python

def A136522(n): return int((s:=str(n))[:(t:=(len(s)+1)//2)]==s[:-t-1:-1]) # Chai Wah Wu, Jun 23 2022

Formula

a(n) = if A004086(n) = n then 1 else 0. - Reinhard Zumkeller, Apr 08 2011

a(n) = A000007(A064834(n)). - Reinhard Zumkeller, Sep 18 2013