A397695 Residue class of the decimal digits of n taken mod 3, with 0 represented by 3, and in nondecreasing order.

3, 1, 2, 3, 1, 2, 3, 1, 2, 3, 13, 11, 12, 13, 11, 12, 13, 11, 12, 13, 23, 12, 22, 23, 12, 22, 23, 12, 22, 23, 33, 13, 23, 33, 13, 23, 33, 13, 23, 33, 13, 11, 12, 13, 11, 12, 13, 11, 12, 13, 23, 12, 22, 23, 12, 22, 23, 12, 22, 23, 33, 13, 23, 33, 13, 23, 33, 13

Offset

0,1

Comments

Also, a(n) is the digits of A397694(n) sorted in nondecreasing order.

Links

Michael S. Branicky, Table of n, a(n) for n = 0..10000

Example

a(57) = 12 since 5 mod 3 = 2 and 7 mod 3 = 1, and 21 sorted in nondecreasing order is 12.
a(68) = 23 since 6 mod 3 = 0 (which is encoded as 3) and 8 mod 3 = 2, and 32 sorted in nondecreasing order is 23.

Mathematica

A397695[n_] := FromDigits[Sort[Mod[IntegerDigits[n], 3] /. 0 -> 3]];
Array[A397695, 100, 0] (* Paolo Xausa, Jul 05 2026 *)

Prog

(Python)
def a(n): return int("".join(sorted(map(str, [(r:=di%3)+3*int(r==0) for di in list(map(int, str(n)))]))))
print([a(n) for n in range(68)])

Crossrefs

Cf. A007932, A010882, A397643, A397644, A397694.

Sequence in context: A153510 A288537 A167373 * A397694 A079722 A079723

Adjacent sequences: A397682 A397691 A397694 * A397715 A397716 A397717

Keyword

nonn,base,easy,new

Author

Michael S. Branicky, Jul 05 2026

Status

approved