A209519 Expansion A(x) = Sum_{n>0} a(n)*x^n/(3^(n-1)*n!), A(x) satisfies A(A(A(x)))=e^x-1.

1, 1, 0, 0, 2, -21, 138, 150, -22833, 303975, 3451320, -214016553, 666006714, 228865308144, -4943013567642, -396567325158381, 21423378444873687, 1022158819761317838, -121532275123709160942

Offset: 1

Author

Vladimir Kruchinin, Mar 10 2012

Keywords

• sign

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..200

Crossrefs

Cf. A184011.

Programs

Maxima

T(n,m):=if n=m then 1 else 1/3*(stirling2(n,m)*m!/n!-sum(T(k,m)*sum(T(n,i)*T(i,k),i,k,n),k,m+1,n-1)-T(m,m)*sum(T(n,i)*T(i,m),i,m+1,n-1));
makelist(n!*3^(n-1)*(T(n,1)),n,1,7);

Formula

a(n)=3^(n-1)*n!*T(n,1), T(n,m)=1/3*(stirling2(n,m)*m!/n!-sum(k=m+1..n-1, T(k,m)*sum(i=k..n, T(n,i)*T(i,k)))-T(m,m)*sum(i=m+1..n-1, T(n,i)*T(i,m))), n>m, T(n,n)=1.