A059249 Tersum n + (n-1); write n and n-1 in base 3 and add mod 3 with no carries.

1, 0, 5, 7, 6, 2, 4, 3, 17, 19, 18, 23, 25, 24, 20, 22, 21, 8, 10, 9, 14, 16, 15, 11, 13, 12, 53, 55, 54, 59, 61, 60, 56, 58, 57, 71, 73, 72, 77, 79, 78, 74, 76, 75, 62, 64, 63, 68, 70, 69, 65, 67, 66, 26, 28, 27, 32, 34, 33, 29, 31, 30, 44, 46, 45, 50, 52, 51, 47, 49, 48, 35

Offset: 1

Author

Henry Bottomley, Jan 22 2001

Keywords

• nonn
• look

Examples

			a(21)=14 since 21 and 20 are written in base 3 as 210 and 202 and so their tersum is 112 in base 3, i.e. 9+3+2=14.
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..19682

Crossrefs

Cf. A004482, A004488, A004489, A038712.