An infinite game (noch nicht übersetzt)
Peter is playing a solitaire game on an infinite checkerboard, each square of which can hold an unlimited number of tokens.
Each move of the game consists of the following steps:
- Choose one token T to move. This may be any token on the board, as long as not all of its four adjacent squares are empty.
- Select and discard one token D from a square adjacent to that of T.
- Move T to any one of its four adjacent squares (even if that square is already occupied).

The board is marked with a line called the dividing line. Initially, every square to the left of the dividing line contains a token, and every square to the right of the dividing line is empty:

Peter's goal is to get a token as far as possible to the right in a finite number of moves. However, he quickly finds out that, even with his infinite supply of tokens, he cannot move a token more than four squares beyond the dividing line.
Peter then considers starting configurations with larger supplies of tokens: each square in the dth column to the left of the dividing line starts with dn tokens instead of 1. This is illustrated below for n=1:

Let F(n) be the maximum number of squares Peter can move a token beyond the dividing line. For example, F(0)=4. You are also given that F(1)=6, F(2)=9, F(3)=13, F(11)=58 and F(123)=1173.
Find F(1234567).