A284797 Write in base k, complement, reverse. Case k = 3.

2, 1, 0, 7, 4, 1, 6, 3, 0, 25, 16, 7, 22, 13, 4, 19, 10, 1, 24, 15, 6, 21, 12, 3, 18, 9, 0, 79, 52, 25, 70, 43, 16, 61, 34, 7, 76, 49, 22, 67, 40, 13, 58, 31, 4, 73, 46, 19, 64, 37, 10, 55, 28, 1, 78, 51, 24, 69, 42, 15, 60, 33, 6, 75, 48, 21, 66, 39, 12, 57, 30

Offset: 0

Author

Paolo P. Lava, Apr 03 2017

Keywords

• nonn
• base
• easy

Examples

			a(9) = 25 because 9 in base 3 is 100, its complement in base 3 is 122 and the digit reverse is 221 that is 25 in base 10.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A036044, A267193, A284798.

Programs

Maple

P:=proc(q,h) local a,b,k,n; print(h-1); for n from 1 to q do a:=convert(n,base,h); b:=0;
for k from 1 to nops(a) do a[k]:=h-1-a[k]; b:=h*b+a[k]; od; print(b); od; end: P(10^2,3);

Mathematica

Table[FromDigits[Reverse[2-IntegerDigits[n,3]],3],{n,0,70}] (* Harvey P. Dale, Sep 08 2019 *)

Python

from gmpy2 import digits
def A284797(n): return -int((s:=digits(n,3)[::-1]),3)-1+3**len(s) # Chai Wah Wu, Feb 04 2022