A103995 First column of triangle A103910.

1, -1, 0, 1, -1, -6, 35, 181, -6056, -3741, 5880885, -149991434, -32148902071, 4867910308359, 891980177502800, -740991835820243639, -53134975005564905081, 626000780698404972023994

Offset

1,6

Comments

The sign of a(n) appears to follow a 7-periodic pattern.

Links

Table of n, a(n) for n=1..18.

Formula

Recurrence: a(n) = -Sum[i=1..n-1, a(i)*A010048(n-1, i-1) ] (conjectured).

Crossrefs

Sequence in context: A026997 A014337 A002041 * A137628 A254826 A274373

Adjacent sequences: A103992 A103993 A103994 * A103996 A103997 A103998

Keyword

sign

Author

Ralf Stephan, Feb 24 2005

Status

approved