A109910 a(n) = 9's complement of digit reversal of n.

9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 8, 88, 78, 68, 58, 48, 38, 28, 18, 8, 7, 87, 77, 67, 57, 47, 37, 27, 17, 7, 6, 86, 76, 66, 56, 46, 36, 26, 16, 6, 5, 85, 75, 65, 55, 45, 35, 25, 15, 5, 4, 84, 74, 64, 54, 44, 34, 24, 14, 4, 3, 83, 73, 63, 53, 43, 33, 23, 13, 3, 2

Offset: 0

Author

Amarnath Murthy, Jul 16 2005

Keywords

• base
• easy
• nonn
• look

Examples

			a(17) = 28. Digit reversal of 17 = 71, 9's complement of 71 is 99-71 = 28.
		

Links

• Nathaniel Johnston, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A004086, A061601, A109911.

Programs

Maple

R := proc(n) local nn, nnn: nn:=convert(n, base, 10): add(nn[nops(nn)+1-j]*10^(j-1), j=1..nops(nn)): end:
A109910 := proc(n) return 10^length(max(R(n),1)) - R(n) - 1: end:
seq(A109910(n),n=0..70); # Nathaniel Johnston, Apr 28 2011

Mathematica

Table[10^If[# == 0, 1, IntegerLength@ #] - 1 - # &@ FromDigits@ Reverse@ IntegerDigits@ n, {n, 0, 70}] (* Michael De Vlieger, Feb 01 2017 *)

Python

def A109910(n):
    x=int(str(n)[::-1])
    return 10**len(str(x))-1-x # Indranil Ghosh, Jan 30 2017

Formula

a(n) = A061601(A004086(n)). - Indranil Ghosh, Jan 30 2017