Sudoku-15up Thumbnail of a Sudoku-15up puzzle.

Size:
15x15.
Elements:
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, and E.
Groups: Forty-five total.
The 15 rows.
The 15 columns.
The 15 3x5 rectangles.
Instructions:
Precise details on group numbering.
Answer grids:

Puzzle Difficulty levels and Examples

Difficulty LevelLowHighExample
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 14 Puzzle   ·   3-steps   ·   All-steps   ·   Solution grid
Challenging 15 20
Tournament 21 29
TournamentPlus 30 45
Perplexing 46 60