A235049 Subtract one from each nonzero digit in decimal representation of n.

0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 20, 20, 21, 22, 23, 24, 25, 26, 27, 28, 30, 30, 31, 32, 33, 34, 35, 36, 37, 38, 40, 40, 41, 42, 43, 44, 45, 46, 47, 48, 50, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60

Offset: 0

Author

Antti Karttunen, Apr 14 2014

Keywords

• nonn
• easy
• base
• look

Comments

Contains exactly the same terms as A007095, except that each occurs an infinite number of times.

A102683(a(n)) = 0. - Reinhard Zumkeller, Apr 16 2014

Examples

			Subtracting one from each nonzero digit of '9', we get 8, thus a(9)=8. Doing same for '10' results '00' thus a(10)=0. For '12', this results '01', thus a(12)=1.
		

Links

• Antti Karttunen, Table of n, a(n) for n = 0..10000
• Index entries for sequences related to decimal expansion of n

Crossrefs

Cf. A007095.

Programs

Haskell

a235049 x = if x == 0 then 0 else 10 * a235049 x' + max 0 (d - 1)
            where (x', d) = divMod x 10
-- Reinhard Zumkeller, Apr 16 2014

Mathematica

a[n_] := FromDigits[If[#>0, #-1, #]& /@ IntegerDigits[n]];
Table[a[n], {n, 0, 100}] (* Jean-François Alcover, Jan 13 2023 *)

Formula

a(0) = 0, and for n>=1, if n = 0 modulo 10, a(n) = 10*a(n/10), otherwise a(n) = 10*a(floor(n/10)) + (n modulo 10) - 1.