Question 631818
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Hi,
General Summation Notation : {{{sum( a[n], n=1, infinity )}}}
{2 + 5 + 8 + 11 + ... + 29} Arithemetic, d = 3 {{{a[n] = 2 + (n-1)3 = 3n-1}}}
   {{{sum( 3n-1, n=1, 10 )}}}

{6 - 12 + 24 - 48 + ...}  Geometric, r = (-2) {{{a[n] = 6(-2)^(n-1)}}} 
{{{sum(6*(-2)^(n-1), n=1, infinity)}}}

{{{c[1]}}} = 2, {{{c[2]}}}= -1, and c[k+2] = {{{c[k]}}} + c[k+1] for k>0 
 { 2, -1, 1, 0, 1, 1, 2, 3 }  previous two terms added to get the next