L.g.f.：L（x，y）=（x+y）/1+（3*x^2+2*x*y+3*y^2）/2+（4*x^3+3*x|2*y+3*x*y^2+4*y^3）/3+（7*x^4+4*x^3*y+10*x^2*y^2+4*x*y ^3+7*y^4）/4+（6*x^5+5*x^4*y+10*x^3*y ^2+10*x ^2*y ^3+5*x*y^4+6*y^5）/5+（12*x^6+6*x^5*y+21*x^4*y^2+26*x^3*y^3+21*x^2*y^4+6*x*y ^5+12*y ^6）/6+（8*x^7+7*x^6*y+21*x^5*y^2+35*x^4*y^3+35*x^3*y^4+21*x ^2*y^5+7*x*y^6+8*y^7）/7+（15*x^8+8*x^7*y+36*x^6*y^2+56*x*y^3+90*x^4*y^4+56*x ^3*y ^5+36*x*y ^6+8*x*y ^7+15*y^8）/8+。。。
这样的话
exp（L（x，y））=产品{n>=1}1/（1-（x^n+y^n）），或
L（x，y）=和{n>=1}-对数（1-（x^n+y^n）），
哪里
L（x，y）=和{n>=0}和{k>=0{T（n，k）*x^n*y^k/（n+k），
其中常数项取零：L（0,0）=0。
方形桌子。
L（x，y）中x^n*y^k/（n+k）的系数T（n，k）的平方表开始
0, 1, 3, 4, 7, 6, 12, 8, 15, 13, 18, 12, 28, 14, ...;
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, ...;
3, 3, 10, 10, 21, 21, 36, 36, 55, 55, 78, 78, 105, ...;
4, 4, 10, 26, 35, 56, 93, 120, 165, 232, 286, 364, ...;
7, 5, 21, 35, 90, 126, 230, 330, 537, 715, 1043, 1365, ...;
6, 6, 21, 56, 126, 262, 462, 792, 1287, 2002, 3018, ...;
12, 7, 36, 93, 230, 462, 994, 1716, 3073, 5035, 8120, ...;
8, 8, 36, 120, 330, 792, 1716, 3446, 6435, 11440, 19448, ...;
15, 9, 55, 165, 537, 1287, 3073, 6435, 13050, 24310, 44010, ...;
13, 10, 55, 232, 715, 2002, 5035, 11440, 24310, 48698, 92378, ...;
18, 11, 78, 286, 1043, 3018, 8120, 19448, 44010, 92378, 185310, ...;
12, 12, 78, 364, 1365, 4368, 12376, 31824, 75582, 167960, 352716, ...; ...
三角形。
或者，这个序列可以写成三角形，从
0;
1, 1;
3, 2, 3;
4, 3, 3, 4;
7, 4, 10, 4, 7;
6, 5, 10, 10, 5, 6;
12, 6, 21, 26, 21, 6, 12;
8, 7, 21, 35, 35, 21, 7, 8;
15, 8, 36, 56, 90, 56, 36, 8, 15;
13, 9, 36, 93, 126, 126, 93, 36, 9, 13;
18, 10, 55, 120, 230, 262, 230, 120, 55, 10, 18;
12, 11, 55, 165, 330, 462, 462, 330, 165, 55, 11, 12;
28, 12, 78, 232, 537, 792, 994, 792, 537, 232, 78, 12, 28;
14, 13, 78, 286, 715, 1287, 1716, 1716, 1287, 715, 286, 78, 13, 14;
24, 14, 105, 364, 1043, 2002, 3073, 3446, 3073, 2002, 1043, 364, 105, 14, 24;
24, 15, 105, 470, 1365, 3018, 5035, 6435, 6435, 5035, 3018, 1365, 470, 105, 15, 24;
31, 16, 136, 560, 1892, 4368, 8120, 11440, 13050, 11440, 8120, 4368, 1892, 560, 136, 16, 31; ...
其中L（x，y）=和{n>=0}和{k=0..n}T（n-k，k）*x^（n-k）*y^k/n。
