A004509 Tersum n + 20.

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

Offset

0,1

Links

Table of n, a(n) for n=0..57.

Formula

Tersum m + n: write m and n in base 3 and add mod 3 with no carries; e.g., 5 + 8 = "21" + "22" = "10" = 1.

Crossrefs

Sequence in context: A376974 A365065 A076119 * A248942 A022976 A023462

Adjacent sequences: A004506 A004507 A004508 * A004510 A004511 A004512

Keyword

nonn

Author

N. J. A. Sloane

Status

approved