例如:A(x,y)=1+(1*x+1*y)+(1x^2+2*x*y+1*y^2)/2!+(1*x^3+6*x^2*y+6*x*y^2+1*y^3)/3!+(1*x^4+16*x^3*y+30*x^2*y^2+16*x*y^3+1*y^4)/4!+(1*x^5+40*x^4*y+140*x^3*y^2+140*x^2*y^3+40*x*y^4+1*y^5)/5!+(1*x^6+96*x^5*y+615*x^4*y^2+1040*x^3*y^3+615*x^2*y^4+96*x*y^5+1*y^6)/6!+(1*x^7+224*x^6*y+2562*x^5*y^2+7000*x^4*y^3+7000*x^3*y^4+2562*x^2*y^5+224*x*y^6+1*y^7)/7!+(1*x^8+512*x^7*y+10220*x^6*y^2+43904*x^5*y^3+68390*x^4*y^4+43904*x^3*y^5+10220*x^2*y^6+512*y^7+1*y^8)/8!+。。。
其中A(x,y)=(cosh(x)*cosh(y)+sinh(x)+sing(y))/(1-sinh(x)*sinh(y)。
这个x^n*y^k/(n+k)系数的平方表!在A(x,y)中开始
1, 1, 1, 1, 1, 1, 1, 1, 1, ...;
1, 2, 6, 16, 40, 96, 224, 512, 1152, ...;
1, 6, 30, 140, 615, 2562, 10220, 39384, 147645, ...;
1, 16, 140, 1040, 7000, 43904, 260736, 1482240, 8131200, ...;
1, 40, 615, 7000, 68390, 605808, 4998210, 39032400, 291662415, ...;
1, 96, 2562, 43904, 605808, 7322112, 80735424, 831080448, 8105175936, ...;
1, 224, 10220, 260736, 4998210, 80735424, 1161583500, 15355426944, ...;
1, 512, 39384, 1482240, 39032400, 831080448, 15355426944, 256124504064, ...; ...
这个序列可以写成三角形,从
1,
1, 1,
1, 2, 1,
1, 6, 6, 1;
1, 16, 30, 16, 1;
1, 40, 140, 140, 40, 1;
1, 96, 615, 1040, 615, 96, 1;
1, 224, 2562, 7000, 7000, 2562, 224, 1;
1, 512, 10220, 43904, 68390, 43904, 10220, 512, 1;
1, 1152, 39384, 260736, 605808, 605808, 260736, 39384, 1152, 1;
1, 2560, 147645, 1482240, 4998210, 7322112, 4998210, 1482240, 147645, 2560, 1; ...
相关系列。
C(x,y)和S(x,y)的级数展开式如下所示
C(x,y)=1+(1*x^2+2*x*y+1*y^2)/2!+(1*x^4+16*x^3*y+30*x^2*y^2+16*x*y^3+1*y^4)/4!+(1*x^6+96*x^5*y+615*x^4*y^2+1040*x^3*y^3+615*x^2*y^4+96*x*y^5+1*y^6)/6!+(1*x^8+512*x^7*y+10220*x^6*y^2+43904*x^5*y^3+68390*x^4*y^4+43904*x^3*y^5+10220*x^2*y^6+512*y^7+1*y^8)/8!+。。。
S(x,y)=(1*x+1*y)+(1*x^3+6*x^2*y+6*x*y^2+1*y^3)/3!+(1*x^5+40*x^4*y+140*x^3*y^2+140*x^2*y^3+40*x*y^4+1*y^5)/5!+(1*x^7+224*x^6*y+2562*x^5*y^2+7000*x^4*y^3+7000*x^3*y^4+2562*x^2*y^5+224*x*y^6+1*y^7)/7!+。。。
其中A(x,y)=C(x,y)+S(x,y^2)-S(x,y-)^2=1。
例如f.可以用系数x^n*y^k/(n!*k!)表示,如下所示:
A(x,y)=1+(1*x+1*y)+(1*x^2/2!+1*x*y+1*y^2/2)+(1*x^3/3!+2*x^2*y/2!+2*x*y^2/2!+1*y^3/3!)+1*y^4/4!)+(1*x^5/5!+8*x^4*y/4!+14*x^3*y^2/(3!*2!)+14*x^2*y^3/(2!*3!)+8*x*y^4/4!+1*y^5/5!)+(1*x^6/6!+16*x^5*y/5!+41*x^4*y^2/(4!*2!)+52*x^3*y^3/(3!*3!)+41*x^2*y^4/(2!*4!)+16*x*y^5/5!+1*y^6/6!)+(1*x^7/7!+32*x^6*y/6!+122*x^5*y^2/(5!*2!)+200*x^4*y^3/(4!*3!)+200*x^3*y^4/(3!*4!)+122*x^2*y^5/(2!*5!)+32*x*y^6/6!+1*y^7/7!)+(1*x^8/8!+64*x^7*y/7!+365*x^6*y^2/(6!*21*y^8/8!)+。。。