As a perl one-liner you could write:
perl -le 'for ($_=-1-2,$i = 0; $i<7; $i++) {$_+= $i*$i }; print'
or without a zero:
perl -le 'print ((7+1)x2)'
or without a zero OR a two in the bash shell:
x=$((7+1)) && echo $x$x
or without a zero, one, or two in bash:
false || x=$((7+$?)) && echo $x$x
or without any numbers at all:
false || x=$(($?+$?+$?+$?+$?+$?+$?+$?)) && echo $x$x