what is the sum of 4+18+48+100+180+294+448+....up to 28 terms?

• 180670
  the series is n[(n+1)^2]...apply the summation formula till n=28
  (n^2)[(n+1)^2]/4 + n(n+1)/2 + 2n(n+1)(2n+1)/6
  put n=28 to get ans= 180670
• 9 years agoHelpfull: Yes(10) No(7)
• "180670"
  the series is " n[(n+1)^2] " in this pattern
  Case 1 put n=1
  u will get "4"
  Case 2 put n="2"
  u will get "18
  Case 3 put n="3"
  u will get "48"
  
  and so on
  put n=28 to get ans= 180670
• 9 years agoHelpfull: Yes(4) No(3)
• Dear pal,I could not get the calculation.Could you explain it plz?
  
• 9 years agoHelpfull: Yes(3) No(1)
• What is the summation formula??@ABHYUDAY PAL
• 9 years agoHelpfull: Yes(3) No(2)
• 180670
  the series is n[(n+1)^2]...apply the summation formula till n=28
  (n^2)[(n+1)^2]/4 + n(n+1)/2 + 2n(n+1)(2n+1)/6
  put n=28 to get ans= 180670
• 9 years agoHelpfull: Yes(2) No(1)
• series can be written as n[(n+1)^2]
  then re-arrange as :-
  (2-1)*2^2+(3-1)*3^2+...........+(29-1)29^2
  (1^3+2^3+3^3+............+29^3) - (1^2+2^2+3^2+........+29^2) = 180670
• 8 years agoHelpfull: Yes(2) No(0)