“…Independently, Mordell also considered these series in [5]. Recently Huard, Williams and Zhang Nan-Yue gave an explicit formula for T(k, I, N -k -I) as a rational linear combination of the products C(2j)<(JV -2j) {0 ^ j ^ (N -3)/2) when N is odd, N > 3, and k,l € N o satisfying l^k + l^N-l, k^N-2&ndl^N-2 (see [3] [1,6,7]). Recently Terhune proved that if x ( -l ) t / ' ( -l ) = ( -l ) formulas for double L-series given in [6,7].…”