Logic Masters Deutschland e.V.

I've been itching to contribute to the Somedoku trend, and being me, there's no better way to do so than with an Octopus. Coincidentally, blackjackfitz has been itching to contribute to the Octopus trend, and being him, there's no better way to do so than with a Somedoku! When we discovered each other's half-finished projects, we decided to collaborate, and have recently completed a very exciting puzzle.

We both had good reason to want it to appear on our own LMD page, so I decided the best compromise would be to cook up a quick practice puzzle for my own page and let him host the main puzzle. Of course, it's me, so this "practice puzzle" ended up rather difficult, arguably more so than the original...

The title refers to the name of my daughter's new favourite toy, which my partner convinced me to buy as a nod to the Octopus sudoku variant.

Many thanks to Marty Sears for letting me borrow his background image, and to my dad for help with testing.

-> Some Octopus (collab with blackjackfitz)
-> Need help?! Watch blackjackfitz's solve of Captain Calamari
-> Try out some more Octopus puzzles



Somedoku: Fill each cell with a digit from 1-9 (not necessarily 1-7). For every row 'n' and column 'n' there are exactly 'n' different digits. The remaining cells are filled with repeats.

Octopus: draw 8 tentacles, all of the same length (in no. of cells) that emanate from the head (r4c4) and reach the edge of the grid, where they stop immediately. Tentacles do not cross or overlap, except at the head. Opposite tentacles are considered as single lines, which have 180 degree rotational symmetry.

The Octopus' four lines are all Parity lines, i.e. adjacent digits on the line must include one even and one odd digit.

Counting Octopus: a digit on the octopus shows how many times that digit appears on the octopus.

Counting Anti-Octopus: a digit that appears in the puzzle but NEVER on the octopus shows how many times it appears in the puzzle.

[To clarify: a digit, N, either appears: (a) N times on the octopus and any number of times off it; (b) N times off the octopus; (c) not at all]

Local constraints: digits in a cage must sum to the indicated total; an inequality sign points to a smaller digit.