cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A111834 Column 0 of the matrix logarithm (A111833) of triangle A111830, which shifts columns left and up under matrix 7th power; these terms are the result of multiplying the element in row n by n!.

Original entry on oeis.org

0, 1, -5, 83, 16110, -40097784, -388036363380, 82804198261002036, 50475967918183333160880, -711988160501968313699728393632, -26438313284970847487368499812182785280, 22571673265500745067336177578868612107537514880
Offset: 0

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Author

Gottfried Helms and Paul D. Hanna, Aug 22 2005

Keywords

Comments

Let q=7; the g.f. of column k of A111830^m (matrix power m) is: 1 + Sum_{n>=1} (m*q^k)^n/n! * Product_{j=0..n-1} A(q^j*x).

Examples

			A(x) = x - 5/2!*x^2 + 83/3!*x^3 + 16110/4!*x^4 - 40097784/5!*x^5 +...
where e.g.f. A(x) satisfies:
x/(1-x) = A(x) + A(x)*A(7*x)/2! + A(x)*A(7*x)*A(7^2*x)/3! +
A(x)*A(7*x)*A(7^2*x)*A(7^3*x)/4! + ...
Let G(x) be the g.f. of A111831 (column 1 of A111830), then
G(x) = 1 + 7*A(x) + 7^2*A(x)*A(7*x)/2! +
7^3*A(x)*A(7*x)*A(7^2*x)/3! +
7^4*A(x)*A(7*x)*A(7^2*x)*A(7^3*x)/4! + ...
		

Crossrefs

Cf. A111830 (triangle), A111831, A111833 (matrix log); A110505 (q=-1), A111814 (q=2), A111816 (q=3), A111819 (q=4), A111824 (q=5), A111829 (q=6), A111839 (q=8).

Programs

  • PARI
    {a(n,q=7)=local(A=x/(1-x+x*O(x^n)));for(i=1,n, A=x/(1-x)/(1+sum(j=1,n,prod(k=1,j,subst(A,x,q^k*x))/(j+1)!))); return(n!*polcoeff(A,n))}

Formula

E.g.f. satisfies: x/(1-x) = Sum_{n>=1} Prod_{j=0..n-1} A(7^j*x)/(j+1).