a(n,m) tabl head (triangle) for A053120 Coefficients for Chebyshev T-polynomials n\m 0 1 2 3 4 5 6 7 8 9 10 11 12 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 2 -1 0 2 0 0 0 0 0 0 0 0 0 0 3 0 -3 0 4 0 0 0 0 0 0 0 0 0 4 1 0 -8 0 8 0 0 0 0 0 0 0 0 5 0 5 0 -20 0 16 0 0 0 0 0 0 0 6 -1 0 18 0 -48 0 32 0 0 0 0 0 0 7 0 -7 0 56 0 -112 0 64 0 0 0 0 0 8 1 0 -32 0 160 0 -256 0 128 0 0 0 0 9 0 9 0 -120 0 432 0 -576 0 256 0 0 0 10 -1 0 50 0 -400 0 1120 0 -1280 0 512 0 0 11 0 -11 0 220 0 -1232 0 2816 0 -2816 0 1024 0 12 1 0 -72 0 840 0 -3584 0 6912 0 -6144 0 2048 This confirms the Abramowitz-Stegun table p.795. The rows n=13 to 20 are: n=13: [0, 13, 0, -364, 0, 2912, 0, -9984, 0, 16640, 0, -13312, 0, 4096] n=14: [-1, 0, 98, 0, -1568, 0, 9408, 0, -26880, 0, 39424, 0, -28672, 0, 8192] n=15: [0, -15, 0, 560, 0, -6048, 0, 28800, 0, -70400, 0, 92160, 0, -61440, 0, 16384] n=16: [1, 0, -128, 0, 2688, 0, -21504, 0, 84480, 0, -180224, 0, 212992, 0, -131072, 0, 32768] n=17: [0, 17, 0, -816, 0, 11424, 0, -71808, 0, 239360, 0, -452608, 0, 487424, 0, -278528, 0, 65536] n=18: [-1, 0, 162, 0, -4320, 0, 44352, 0, -228096, 0, 658944, 0, -1118208, 0, 1105920, 0, -589824, 0, 131072] n=19: [0, -19, 0, 1140, 0, -20064, 0, 160512, 0, -695552, 0, 1770496, 0, -2723840, 0, 2490368, 0, -1245184, 0, 262144] n=20: [1, 0, -200, 0, 6600, 0, -84480, 0, 549120, 0, -2050048, 0, 4659200, 0, -6553600, 0, 5570560, 0, -2621440, 0, 524288][1, 0, -200, 0, 6600, 0, -84480, 0, 549120, 0, -2050048, 0, 4659200, 0, -6553600, 0, 5570560, 0, -2621440, 0, 524288] ####################################### e.o.f. #######################################################