A107728 Matrix inverse of A107722.

1, -2, 1, -4, -4, 1, -26, -8, -6, 1, -262, -52, -14, -8, 1, -3482, -524, -102, -22, -10, 1, -56902, -6964, -1130, -184, -32, -12, 1, -1099514, -113804, -16326, -2304, -306, -44, -14, 1, -24494422, -2199028, -287882, -37224, -4326, -476, -58, -16, 1, -617906906, -48988844, -5969382, -727928, -78114

Offset

0,2

Comments

Column 0 shift left = -2*A107721, where A107721 = column 1 of A107719. Column 1 shift left = 2*(column 0) shift left. Matrix square of A107727.

Links

Table of n, a(n) for n=0..49.

Example

Triangle begins:
1;
-2,1;
-4,-4,1;
-26,-8,-6,1;
-262,-52,-14,-8,1;
-3482,-524,-102,-22,-10,1;
-56902,-6964,-1130,-184,-32,-12,1;
-1099514,-113804,-16326,-2304,-306,-44,-14,1; ...

Prog

(PARI) {T(n, k)=local(L, N, M=matrix(n+1, n+1, m, j, if(m>=j, if(m==j, 1, if(m==j+1, -3*j, polcoeff(1/sum(i=0, m-j, prod(r=0, i-1, 3*r+1)*x^i)+O(x^m), m-j)))))^-1); L=sum(i=1, #M, (M^0-M)^i/i)/3; N=sum(i=0, #L, L^i/i!); return(if(n<0, 0, (N^2)[n+1, k+1]))}

Crossrefs

Cf. A107719, A107721, A107722, A107727.

Sequence in context: A108556 A122440 A046943 * A128250 A086145 A309086

Adjacent sequences: A107725 A107726 A107727 * A107729 A107730 A107731

Keyword

sign,tabl

Author

Paul D. Hanna, May 30 2005

Status

approved