A081732 Number of numbers that differ from n in ternary representation by exactly one edit-operation: deletion, insertion, or substitution.

4, 6, 6, 11, 10, 11, 11, 11, 10, 14, 15, 15, 15, 14, 15, 16, 16, 15, 14, 15, 15, 16, 15, 16, 15, 15, 14, 18, 19, 19, 20, 19, 20, 20, 20, 19, 19, 20, 20, 19, 18, 19, 20, 20, 19, 20, 21, 21, 21, 20, 21, 20, 20, 19, 18, 19, 19, 20, 19, 20, 20, 20, 19, 20, 21, 21, 20, 19, 20, 21

Offset

0,1

Comments

a(n) = #{j: LD-3(n,j)=1}, where LD-3 is the Levenshtein distance on ternary strings.

Links

Table of n, a(n) for n=0..69.

Michael Gilleland, Levenshtein Distance. [It has been suggested that this algorithm gives incorrect results sometimes. - N. J. A. Sloane]

Example

n=12: ternary representation of numbers at Levenshtein distance 1 from 12='110':
{10, 11, 100, 111, 112, 120, 210, 1010, 1100, 1101,
1102, 1110, 1120, 1210, 2110}, therefore a(12)=15.
n=42: ternary representation of numbers at Levenshtein distance 1 from 42='1120':
{110, 112, 120, 1020, 1100, 1110, 1121, 1122, 1220,
2120, 10120, 11020, 11120, 11200, 11201, 11202, 11210, 11220, 12120, 21120},
therefore a(42)=20.

Crossrefs

Cf. A080950, A080910, A007089.

Sequence in context: A369749 A193814 A304409 * A079033 A272771 A346675

Adjacent sequences: A081729 A081730 A081731 * A081733 A081734 A081735

Keyword

nonn,base

Author

Reinhard Zumkeller, Apr 06 2003

Status

approved