#Life 1.05 #D Irrational 5 #D Population growth is linear with an irrational multiplier. #D Each middleweight spaceship produced by the puffers either hits a #D boat or is deleted by a glider. Denoting the first possibility by #D 1 and the second by 0, we obtain a sequence beginning 101011011010... #D If we prepend 101, we obtain the Fibonacci string sequence, defined #D by starting with 1 and then repeatedly replacing each 0 by 1 and each #D 1 by 10: 1 -> 10 -> 101 -> 10110 -> 10110101 -> ... (See Knuth's #D "The art of computer programming, vol. 1", exercise 1.2.8.36 for #D another definition.) The density of 1's in this sequence is #D (sqrt(5)-1)/2, which implies that the population in gen t is #D asymptotic to (8 - 31 sqrt(5)/10) t. More specifically, the #D population in gen 20 F[n] - 92 (n>=6) is 98 F[n] - 124 F[n-1] + 560, #D where F[n] is the n'th Fibonacci number. (F[0]=0, F[1]=1, and #D F[n] = F[n-1] + F[n-2] for n>=2.) #D Dean Hickerson, dean@ucdmath.ucdavis.edu 5/12/91 #N #P -67 -32 ..** .**** **.** .** . . . ....* ...* ..** ...** ....* . . ..** .**** **.** .** #P -62 -25 * .* .* ..* *** #P -58 -31 **** *...* * .*..* #P -57 -26 ....** ....** ..*...* .*...* *....* .*.* #P -49 -16 ..** .**** **.** .** #P -58 -8 .** **.** .**** ..** . . ....* ...** ..** ...* ....* . . . .** **.** .**** ..** #P -53 -2 ** ...* .*.* ....* *..* ...* .* #P -49 5 .* * *...* **** #P -73 10 .** **.** .**** ..** . . ....* ...** ..**.* ...*.* ....** . . . .** **.** .**** ..** #P -64 16 ...*** .....* ...*** *** #P -64 9 .* * *...* **** #P -56 25 ..** .**** **.** .** #P -48 21 .** ** ..* #P -43 16 .** ** ..* #P -38 11 .** ** ..* #P -33 6 .** ** ..* #P -28 1 .** ** ..* #P -40 -10 .** **.** .**** ..** #P -26 -12 ....* .....* *....* .***** #P -17 -3 .** **.** .**** ..** . . ....* ...** ..** ...** . . . . .** **.** .**** ..** #P -8 -4 .* * *...* **** #P -5 -16 ...* ....* *...* .**** #P 1 12 ..** .**** **.** .** #P 5 1 ..** **.** **** .** #P 13 -13 .**** *...* ....* ...* . . .* ..* ..* .** * . . . .**** *...* ....* ...* #P 22 9 .** **.*** .***** ..*** #P 26 -3 ..* *.* .** #P 31 -8 ..* *.* .** #P 36 -13 ..* *.* .** #P 41 -18 ..* *.* .** #P 46 -23 ..* *.* .** #P 52 -29 ...* ....* *...* .**** #P 36 8 .**** *...* ....* ...* #P 69 -26 .**** *...* ....* ...* . . ** *.* ..* *** . . . . .**** *...* ....* ...* #P 60 -20 ....** ..* .*..* ** .** #P 61 -12 ..** **.** **** .** #P 54 -8 .**** *...* ....* *..* . . ** ..* ..* .** * . . . .**** *...* ....* ...* #P 51 -3 .** *** * *** .* ..* #P 46 -8 ..** **.** **** .** #P 45 12 ...* ....* *...* .**** #P 63 14 ...* ....* *...* .**** . . . * .** ..* ..* ** . . ...* ....* *...* .**** #P 61 21 .* ** .* .* #P 52 21 .....* ..**** .***** * .** ..* #P 55 28 .** **** **.** ..**