A078921 Signed variant of A077012.

1, -1, 2, 2, -3, 6, -6, 8, -12, 24, 24, -30, 40, -60, 120, -120, 144, -180, 240, -360, 720, 720, -840, 1008, -1260, 1680, -2520, 5040, -5040, 5760, -6720, 8064, -10080, 13440, -20160, 40320, 40320, -45360, 51840, -60480, 72576, -90720, 120960, -181440, 362880, -362880, 403200, -453600, 518400, -604800

Offset

1,3

Comments

Row sums give A024167.

Links

Table of n, a(n) for n=1..50.

Formula

a[n, k]= -(-1)^(n-k+1) n/(n-k+1)(n-1)!

E.g.f.: log(1+x)/(1-y*x). - Vladeta Jovovic, Feb 07 2003

Example

Triangle starts {1}, {-1, 2}, {2, -3, 6}, {-6, 8, -12, 24}, {24, -30, 40, -60, 120}, ...

Mathematica

Table[Table[ -(-1)^(n-k+1) n/(n-k+1), {k, 1, n}] (n-1)!, {n, 1, 12}]

Crossrefs

Cf. A077012, A078922, A000254.

Sequence in context: A093784 A035560 A077012 * A011961 A182713 A229626

Adjacent sequences: A078918 A078919 A078920 * A078922 A078923 A078924

Keyword

easy,sign,tabl

Author

Wouter Meeussen, Dec 14 2002

Status

approved