Using [generalized factorial(or multifactorial or k-torial)](https://en.wikipedia.org/wiki/Double_factorial#Generalizations) we obtain: 1: >! 100=11!!!!!!+11!!!!!!!+1 2: >! 100=22!!!!!!!!!!!!!!!!!!+(2+2)!/2 3: >! 100=((3!)!!)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!+3!-(3!+3!)/(3!) 4: >! 100=(4!)!!!!!!!!!!!!!!!!!!!!+4+(4-4)/4 5: >! 100=(5!!)!!!!!!!!!+5+5+5-5 6: >! 100=(6!!)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!+6-(6+6)6 7: >! 100=(7!!!)!!!!!!!!!!!!!!!!!!!!!!!!!+7!!!!!+(7+7)/7 8: >! 100=(8!!!!+8!!!!!!+(8+8)/8)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 9: >! 100=((9+9/9)!!!!!)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!+9-9 --- So we got 100 using all the i's from 1 to 9. --- Edit: I found a formula that works for a any integer greater than 9: >! $$100=\left(\left(\left(\frac{\left(\frac{(n+n){!}_{(n)}}{n+n}\right){\large!}_{(n-5)}}{n}\right){\huge!}_{(3)}\right){\huge!}_{(5)}\right){\huge!}_{(48)}$$ >! where $a!_{(b)}=a\overbrace{!!!\cdots!!!}^{b\mbox{ times}}$ We can write a formula for every number without using $.i$