A004086 Read n backwards (referred to as R(n) in many sequences).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 11, 21, 31, 41, 51, 61, 71, 81, 91, 2, 12, 22, 32, 42, 52, 62, 72, 82, 92, 3, 13, 23, 33, 43, 53, 63, 73, 83, 93, 4, 14, 24, 34, 44, 54, 64, 74, 84, 94, 5, 15, 25, 35, 45, 55, 65, 75, 85, 95, 6, 16, 26, 36, 46, 56, 66, 76, 86, 96, 7, 17, 27, 37, 47

Offset

0,3

Comments

Also called digit reversal of n.

Leading zeros (after the reversal has taken place) are omitted. - N. J. A. Sloane, Jan 23 2017

For n>0: a(a(n)) = n iff n mod 10 != 0. - Reinhard Zumkeller, Mar 10 2002

Links

Indranil Ghosh, Table of n, a(n) for n = 0..50000 (first 1001 terms from Franklin T. Adams-Watters)

Dana G. Korssjoen, Biyao Li, Stefan Steinerberger, Raghavendra Tripathi, and Ruimin Zhang, Finding structure in sequences of real numbers via graph theory: a problem list, arXiv:2012.04625 [math.CO], Dec 08 2020.

Michael Penn, A digit moving number puzzle., YouTube video, 2022.

Formula

a(n) = d(n,0) with d(n,r) = if n=0 then r, otherwise d(floor(n/10), r*10+(n mod 10)). - Reinhard Zumkeller, Mar 04 2010

a(10*n+x) = x*10^m + a(n) if 10^(m-1) <= n < 10^m and 0 <= x <= 9. - Robert Israel, Jun 11 2015

Maple

read transforms; A004086 := digrev; #cf "Transforms" link at bottom of page
A004086:=proc(n) local s, t; if n<10 then n else s:=irem(n, 10, 't'); while t>9 do s:=s*10+irem(t, 10, 't') od: s*10+t fi end; # M. F. Hasler, Jan 29 2012

Mathematica

Table[FromDigits[Reverse[IntegerDigits[n]]], {n, 0, 75}]
IntegerReverse[Range[0, 80]](* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 13 2018 *)

Prog

(PARI) dig(n) = {local(m=n, r=[]); while(m>0, r=concat(m%10, r); m=floor(m/10)); r}
A004086(n) = {local(b, m, r); r=0; b=1; m=dig(n); for(i=1, matsize(m)[2], r=r+b*m[i]; b=b*10); r} \\ Michael B. Porter, Oct 16 2009
(PARI) A004086(n)=fromdigits(Vecrev(digits(n))) \\ M. F. Hasler, Nov 11 2010, updated May 11 2015, Sep 13 2019
(Haskell) a004086 = read . reverse . show  -- Reinhard Zumkeller, Apr 11 2011
(Python)
def A004086(n):
    return int(str(n)[::-1]) # Chai Wah Wu, Aug 30 2014
(J) |.&.": i.@- 1e5 NB. Stephen Makdisi, May 14 2018

Crossrefs

Cf. A004185, A004186, A009996, A073138, A188649, A221714.

Cf. A030101, A030102, A030103, A030104, A030105, A030107, A030108.

Sequence in context: A161594 A084011 A345110 * A121760 A061816 A083960

Adjacent sequences: A004083 A004084 A004085 * A004087 A004088 A004089

Keyword

nonn,base,nice,look

Author

N. J. A. Sloane

Extensions

Extended by Ray Chandler, Dec 30 2004

Status

approved