Janko.at attributes this puzzle to Leonid Mochalov.
Puzzle and Goal
An unsolved puzzle consists of a rectangular grid filled with numbers.
The goal is to draw a single line through orthogonally neighboring cells, starting at the upper left and ending at the lower right.
This is basically a maze using numbers; the name translates to "integer snake".
The solved grid must satisfy the following conditions:
The path must contain every number from the one in the upper left to the one in the lower right exactly once, although not in consecutive order.