A115513 Inverse of matrix (1,x)+(x,x^3).

1, -1, 1, 0, 0, 1, 0, 0, 0, 1, 1, -1, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 1, 0, 0, -1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, -1, 1, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0

Offset

0,1

Comments

Row sums are A014578(n+5) or sum{k=0..ceiling(log(n+4)/log(3)),(-1)^k*(floor((n+4)/3^k)-floor((n+3)/3^k)}. Inverse of number triangle A115512.

Links

Table of n, a(n) for n=0..118.

Example

Triangle begins
1,
-1, 1,
0, 0, 1,
0, 0, 0, 1,
1, -1, 0, 0, 1,
0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 1,
0, 0, -1, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
0, 0, 0, -1, 0, 0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,
-1, 1, 0, 0, -1, 0, 0, 0, 0, 0, 0, 0, 0, 1,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1

Crossrefs

Cf. A014578, A115512.

Sequence in context: A128189 A303340 A115512 * A133080 A316917 A133985

Adjacent sequences: A115510 A115511 A115512 * A115514 A115515 A115516

Keyword

sign,tabl

Author

Paul Barry, Jan 23 2006

Status

approved