Sudoku-7D

Size:

7x7.

Elements:

1, 2, 3, 4, 5, 6, and 7.

Groups: Twenty-one total.

The 7 rows.

The 7 columns.

The 7 septominos.

Instructions:

Precise details on group numbering.

Answer grids:

There are 473,760 answer grids,

(including all possible symetrically equivalent grids)

Puzzle Difficulty levels and Examples

Difficulty Level	Low	High	Example
Easiest	2	2	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Easy	3	4	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Medium	5	8	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Difficult	9	12	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Challenging	13	14	Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid