1*1!+2*2!+3*3!................2012*2012!= ?

• 1(1!)=1=2!-1=1
  1(1!)+2(2!)=5=3!-1=5
  1(1!)+2(2!)+3(3!)=23=4!-1=23
  Similarly,1(1!)+2(2!)+3(3!)+................ +2012(2012!)=2013!-1
  Answer is 2013!-1
• 9 years agoHelpfull: Yes(30) No(0)
• 1(1!)+2(2!)+3(3!)+...+n(n!)= (n+1)!-1 for all positive integers n.
  (2012+1)!-1=2013!-1
• 9 years agoHelpfull: Yes(8) No(0)
• 1*1!+2*2!+3*3!=1+4+18
  =23
  =4!-1=(n+1)!-1
  so for the above problem,
  2013!-1
• 9 years agoHelpfull: Yes(2) No(0)