The pure recurrence operator, in n,  annihilatating the (2n,2n,2n) mixed mom\
    ent of the Ekhad-Zeilberger tri-variate distribution

                where the shift operator is n is denoted by N is


                   There is hope for a recurrence of order, 2

                            2          3          3         3
ope := - 4 (2 n + 3) (n + 1)  (2 n + 1)  (1 + 2 c)  (-1 + c)

                              /         7
    (2 c n + 3 c + 4 n + 7)  /  ((c + 1)  (2 c n + c + 4 n + 3)) + (2 n + 3) (
                            /

       5  3       5  2       4  3       5          4  2        3  3      5
    8 c  n  + 28 c  n  - 64 c  n  + 30 c  n - 220 c  n  - 256 c  n  + 9 c

            4          3  2        2  3       4         3          2  2
     - 232 c  n - 936 c  n  - 224 c  n  - 69 c  - 1068 c  n - 832 c  n

             3        3        2            2       3        2
     - 80 c n  - 368 c  - 972 c  n - 296 c n  - 32 n  - 348 c  - 350 c n

            2                           /         4                           2
     - 120 n  - 129 c - 144 n - 55) N  /  ((c + 1)  (2 c n + c + 4 n + 3)) + N
                                      /

-4*(2*n+3)*(n+1)^2*(2*n+1)^3*(1+2*c)^3*(-1+c)^3*(2*c*n+3*c+4*n+7)/(c+1)^7/(2*c*
n+c+4*n+3)+(2*n+3)*(8*c^5*n^3+28*c^5*n^2-64*c^4*n^3+30*c^5*n-220*c^4*n^2-256*c^
3*n^3+9*c^5-232*c^4*n-936*c^3*n^2-224*c^2*n^3-69*c^4-1068*c^3*n-832*c^2*n^2-80*
c*n^3-368*c^3-972*c^2*n-296*c*n^2-32*n^3-348*c^2-350*c*n-120*n^2-129*c-144*n-55
)/(c+1)^4/(2*c*n+c+4*n+3)*N+N^2
                   -----------------------------------------

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