Generating function
$$U_{1186}(x, y) = \frac{\frac{2 x}{\left(1 - y\right)^{2}} + \sqrt{\frac{4 x^{2}}{\left(1 - y\right)^{4}} + 1}}{\left(1 - y\right)^{3}}$$
Explicit formula
$$Tsqrt2(n, k) = \begin{cases}\frac {k \binom{n+j}{n} \binom{2n+2j}{n+j}} {\binom{2j}{j} {n+k}} &\text{if n+k even, where j =} \frac{n+k} {2},\\\frac {k \binom{n+j}{n} \binom{2n+2j}{n+j}} {\binom{2j}{j} {n+k}} &\text{if n+k odd, where j =} \frac{n+k+1} {2},\\\end{cases} $$$$T_{1186}(n, m, k) = k \operatorname{Tsqrt_{2}}{\left(n,k \right)} {\binom{3 k + m + 2 n - 1}{m}}$$
Data table
1 3 6 1 15 21 28
2 1 3 7 14 252 42
2 14 56 168 42 924 1848
0 0 0 0 0 0 0
-2 -22 -132 -572 -2002 -6006 -16016
0 0 0 0 0 0 0
4 60 480 2720 12240 46512 155040
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