Longest non self loop interaction 2022-04-13: 860 @ 295,147,905,179,352,826,087 [0.295 E21] Code from 1 #!/bin/bash i=1 while true; do c=1 n=$i printf "$n" while [[ $n != "1" ]]; do # bc has no limit for the number of digits (as much as memory can hold) case $n in *0 | *2 | *4 | *6 | *8) n=$( echo "$n / 2"|bc) ;; *) n=$( echo "$n * 3 + 1"|bc) ;; esac printf " -> $n" c=$((c+1)) done echo " [$c]" # maybe use bc .... i=$((i+1)) done Code from 2^68 #!/bin/bash export BC_LINE_LENGTH=0 i=295147905179352825856 while true; do c=1 n=$i printf "$n" while [[ $n != "1" ]]; do case $n in *0 | *2 | *4 | *6 | *8) n=$( echo "$n / 2"|bc) ;; *) n=$( echo "$n * 3 + 1"|bc) esac printf " -> $n" c=$((c+1)) ...