A117399 Column 1 (divided by 2) of triangle A117398, which is the matrix log of A117396.

1, 1, 2, 7, 34, 202, 1402, 11122, 99322, 986362, 10784122, 128720122, 1665516922, 23220588922, 347025670522, 5534133996922, 93802153836922, 1683934185324922, 31917365573484922, 636941680764780922, 13348854673487724922

Offset: 1

Author

Paul D. Hanna, Mar 11 2006

Keywords

• nonn

Links

• G. C. Greubel, Table of n, a(n) for n = 1..250

Crossrefs

Cf. A117398, A117396.

Programs

Mathematica

m=42;
M= Table[If[k>n-1, 0, If[k==n-1, n, -1]], {n,0,m+1}, {k,0,m+1}];
T:= T= Sum[MatrixPower[M, j]/j, {j,m+1}];
Table[T[[n+1, 2]]/2, {n,2,30}] (* G. C. Greubel, Sep 06 2022 *)

PARI

{a(n)=local(M=matrix(n+4,n+4,r,c,if(r>=c,if(r==c+1,-c,1))), L=sum(m=1,n+4,(M^0-M)^m/m));L[n+2,2]/2}