#Imperative programming in make
square = $(shell echo $$(($1 * $1)))

nums := 1 2 3 4 68 8 89
squares := $(foreach n,$(nums),$(call square,$(n)))

all:
	@echo Squares: $(squares)
#all:
#If you uncomment this, it will limit the amount of times you can run the makefile to 3.
#	@echo 'all:' > Makefile
#	@echo '	@echo '\''all:'\'' > Makefile' >> Makefile
#	@echo '	@echo '\''	@echo '\\\'\''all:'\\\'\'''\'\'' > Makefile'\'' >> Makefile' >> Makefile