A105529 Given a list of ternary numbers, interpret each as a ternary modular Gray code number, then convert to decimal.

0, 1, 2, 4, 5, 3, 8, 6, 7, 13, 14, 12, 17, 15, 16, 9, 10, 11, 26, 24, 25, 18, 19, 20, 22, 23, 21, 40, 41, 39, 44, 42, 43, 36, 37, 38, 53, 51, 52, 45, 46, 47, 49, 50, 48, 27, 28, 29, 31, 32, 30, 35, 33, 34, 80, 78, 79, 72, 73, 74, 76, 77, 75

Offset: 0

Author

Gary W. Adamson, Apr 11 2005

Keywords

• nonn
• easy

Examples

			a(9) = 13 since Ternary 100 (9 decimal) interpreted as Ternary Gray code = 13.
		

Links

• Index entries for sequences that are permutations of the natural numbers

Crossrefs

Cf. A105530 (inverse), A128173 (ternary reflected), A006068 (binary), A226134 (decimal modular), A007089.

Programs

Mathematica

a[n_] := Module[{v = IntegerDigits[n, 3]}, Do[v[[i]] = Mod[v[[i]]+v[[i-1]], 3], {i, 2, Length[v]}]; FromDigits[v, 3]];
Table[a[n], {n, 0, 62}] (* Jean-François Alcover, Jun 26 2023, after Kevin Ryde *)

PARI

a(n) = my(v=digits(n,3)); for(i=2,#v, v[i]=(v[i]+v[i-1])%3); fromdigits(v,3); \\ Kevin Ryde, May 23 2020

Extensions

More terms from Sean A. Irvine, Feb 09 2012

Comments by Gary W. Adamson moved to A105530 where they better apply. - Kevin Ryde, May 30 2020