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One-dimensional game of life and its growth functionsDOI: 10.1155/s0161171292000656 Keywords: game of Life , growth functions. Abstract: We start with finitely many 1's and possibly some 0's in between. Then each entry in the other rows is obtained from the Base 2 sum of the two numbers diagonally above it in the preceding row. We may formulate the game as follows: Define d1,j recursively for 1, a non-negative integer, and j an arbitrary integer by the rules:d0,j={1 ¢ € ‰ ¢ € ‰ ¢ € ¢ € ¢ € for ¢ € ‰ ¢ € ‰ ¢ € ‰j=0,k ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € (I)0 ¢ € ‰ ¢ € ‰ ¢ € ‰or ¢ € ‰ ¢ € ‰ ¢ € ‰1 ¢ € ‰ ¢ € ‰ ¢ € ‰for ¢ € ‰ ¢ € ‰ ¢ € ‰0k ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € ‰ ¢ € ‰ ¢ € ‰ ¢ € ‰ ¢ € ‰ ¢ € ¢ € (II)di+1,j=di,j+1(mod2) ¢ € ‰ ¢ € ‰ ¢ € ‰for ¢ € ‰ ¢ € ‰ ¢ € ‰i ¢ ‰ ¥0. ¢ € ¢ € ¢ € ¢ € ¢ € ¢ € (III)Now, if we interpret the number of 1's in row i as the coefficient ai of a formal power series, then we obtain a growth function, f(x)= ¢ ‘i=0 ¢ aixi. It is interesting that there are cases for which this growth function factors into an infinite product of polynomials. Furthermore, we shall show that this power series never represents a rational function.
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