A091174 Leftmost column of triangle A091173, in which the n-th row lists the coefficients of the polynomial that generates the n-th diagonal.

1, 1, 1, 2, 4, 10, 30, 106, 420, 1818, 8530, 43430, 240208, 1439850, 9304070, 64403138, 474740644, 3708087226, 30560873242, 264810927102, 2404843230640, 22825442299962, 225893502009054, 2326337105570074, 24888766556869700, 276246054635709850

Offset

0,4

Comments

The leftmost column of A091173 is determined by the condition that the root of each row polynomial is -1.

The first negative term occurs at index n=158.

Links

Paul D. Hanna, Table of n, a(n) for n = 0..200

Prog

(PARI) /* Set MAX to the number of desired terms to compute */
MAX=30; M091173=matrix(MAX+1, MAX+1, r, c, if(r==c || c==1, 1));
A091173(n, k)=M091173[n+1, k+1]=if(n==k, 1, if(n>k && k>0, sum(j=0, n-k, M091173[n-k+1, j+1]*k^j), if(k==0, -sum(j=1, n, A091173(n, j)*(-1)^j))))
for(n=0, MAX, for(k=0, n, A091173(n, k)); print1(M091173[n+1, 1], ", "))

Crossrefs

Cf. A091173, A091175.

Sequence in context: A050397 A186021 A332650 * A005193 A317280 A173940

Adjacent sequences: A091171 A091172 A091173 * A091175 A091176 A091177

Keyword

sign

Author

Paul D. Hanna, Dec 25 2003

Status

approved