A056965 a(n) = n - (reversal of digits of n).

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, -9, -18, -27, -36, -45, -54, -63, -72, 18, 9, 0, -9, -18, -27, -36, -45, -54, -63, 27, 18, 9, 0, -9, -18, -27, -36, -45, -54, 36, 27, 18, 9, 0, -9, -18, -27, -36, -45, 45, 36, 27, 18, 9, 0, -9, -18, -27, -36, 54, 45, 36, 27, 18, 9, 0, -9, -18, -27, 63, 54, 45, 36, 27, 18, 9, 0, -9, -18, 72, 63, 54

Offset: 0

Author

Henry Bottomley, Jul 18 2000

Keywords

• base
• sign
• look

Comments

a(n) is a multiple of 9.

Examples

			a(17) = 17 - 71 = -54.
		

Links

• Reinhard Zumkeller, Table of n, a(n) for n = 0..10000
• Index entries for the Kaprekar map

Crossrefs

Cf. A004086, A056964, A068396, A151949, A265326.

Programs

Haskell

a056965 n = n - a004086 n  -- Reinhard Zumkeller, Sep 17 2013

Maple

a:= n-> (s-> n-parse(cat(s[-i]$i=1..length(s))))(""||n):
seq(a(n), n=0..82);  # Alois P. Heinz, Jul 11 2021

Mathematica

Table[n - FromDigits[Reverse[IntegerDigits[n]]], {n, 0, 82}] (* Jayanta Basu, Jul 11 2013 *)

PARI

a(n) = n - fromdigits(Vecrev(digits(n))); \\ Michel Marcus, Dec 20 2023

Python

def a(n): return n - int(str(n)[::-1]) # Osman Mustafa Quddusi, Jul 11 2021

Formula

a(n) = n - A004086(n) = 2*n - A056964(n).