login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A181347
Numerators of lower triangular matrix T:=log(F), with the matrix F:=A037027 (Fibonacci convolution matrix).
2
0, 1, 0, 1, 2, 0, -1, 2, 3, 0, -1, -1, 3, 4, 0, 2, -2, -3, 4, 5, 0, 2, 4, -1, -2, 5, 6, 0, -31, 4, 2, -4, -5, 6, 7, 0, -3, -31, 2, 8, -5, -3, 7, 8, 0, 202, -3, -31, 8, 10, -2, -7, 8, 9, 0, 4, 404, -9, -62, 2, 4, -7, -4, 9, 10, 0, -464, 8, 202, -6, -31, 4, 14, -8, -9, 10, 11, 0, -2048, -928, 12, 808, -3, -31, 14, 16, -3, -5, 11, 12, 0
OFFSET
0,5
COMMENTS
The denominator triangle is given by A181348.
Because exp(T) = F, T may be considered as generator of F.
This should be read as N x N matrix for N>=2: log(F_N) := -sum(((-1)^k)/k)*(F_N - Id_N)^k,N-1) with the lower triangular N x N matrix F_N := Matrix([seq([seq(A037027(n,m),n=0..N-1)],m=0..N-1)]) and the N x N identity matrix Id_N.
The log series terminates because of the lower triangular property, and the fact that all main diagonal elements are 1, which follows from
F = Riordan matrix (Fib(x),x*Fib(x)) with the o.g.f. Fib(x)=1/(1-x-x^2). For this notation of Riordan arrays see, e.g., the W.Lang link given in A006232, and there the paragraph "Summary on A- and Z-sequences for Riordan matrices", as well as the 1991 Shapiro et al. reference on the Riordan group given in A053121.
FORMULA
a(n,m) = numerator((log F)(n,m)), with the Fibonacci lower triangular matrix F=A037027.
EXAMPLE
[0]; [1,0]; [1,2,0]; [-1,2,3,0]; [-1,-1,3,4,0];...
The rational triangle (with main diagonal elements 0) starts with the rows [0]; [1, 0]; [1, 2, 0]; [-1/2, 2, 3, 0]; [-1/3, -1, 3, 4, 0];...
CROSSREFS
Sequence in context: A199238 A346698 A352515 * A014587 A354388 A025658
KEYWORD
sign,easy,tabl
AUTHOR
Wolfdieter Lang, Oct 15 2010
STATUS
approved