sa[n_,k_]:=sa[n,k]=a[n+1-k,1]+如果[n<2k,0,-sa[n-k,k]];
a[1,1]:=1;a[n_,1]:=a[n,1]=和[a[i,1]sa[n-1,i]i,{i,1,n-1}]/(n-1);
a[n_,k_]:=a[n,k]=和[a[i,1]a[n-i,k-1],{i,1,n-1}];
nmax=30;A[x_]:=总和[A[i,1]x^i,{i,0,nmax}]
跌落[系数列表[系列[(4A[x]^4+37A[x]^5+12A[x]*6A[x'^3A[x^2]-10A[x=^4A[x ^2]-4A[x|2]^2-17A[x]A[x*2]^2-2A[x~2]^3+2A[x]A[x*4])/8+^4安[x^2]-96安[x]^5安[x|2]-24安[x]^6安[x ^2]-21安[x]^2安[x*2]^2+21安[x]^3+6安[x]^2安[x^2]^3+4安[x*3]^2-4安[x]安[x|3]^2+24安[x^2]安[x_4]-18安[x ^2]阿[x^4]-6安[x]^2安[x^4]-4安[x*6]+4安[x]A[x ^6])/(24(1-A[x]))+A[x]5(2安[x]+67安[x)^2+46安[x]^3+6 A[x]^4-3 A[x^2]-6 A[x]A[x ^2]-2 A[x]^2 A[x ^2])/(2(1-A[x)^2)-A[x^2]+13安[x^2]^2+31安[x]A[x^2]^2+2安[x]^2安[x*2]^2+15安[x|2]^3+5安[x]A[x ^2]^3-3A[x^4]-5A[x]A[x ^4]-3安[x ^2]安[x*4]-A[x]A[x*4]安[x ^2]安[x^2]安[x ^4])/(4(1-A[x*2]))+A[x]^6(4A[x]+153安[x]2+75安[x]^3+12安[x]^4-3安[x^2]-3安[x]A[x ^2])/(6(1-A[x])^3)-A[x]|2安[x|2]^2(2A[x]+7A[x|^2+5安[x>^3+A[x^2]-A[x^3]-A[x ^2][x]A[x]A[x*2])/(2(1-A[x])(1-A[x^2]))+A[x]A[x^3]^2/A[x^2])/(1-A[x^2])^2+A[x]A[x*4]^2/^5/(1-A[x^2])^3+3(1+A[x]