OFFSET
1,9
FORMULA
The first formulas (stripped of factorials) :
1,
k,
k + k^2,
k + 3 k^2 + 2 k^3,
2 k + 9 k^2 + 10 k^3 + 3 k^4,
2 k + 25 k^2 + 50 k^3 + 35 k^4 + 8 k^5,
-12 k + 86 k^2 + 270 k^3 + 260 k^4 + 102 k^5 + 14 k^6,
-120 k + 140 k^2 + 1344 k^3 + 2030 k^4 + 1260 k^5 + 350 k^6 + 36 k^7,
...
EXAMPLE
CROSSREFS
KEYWORD
sign,tabl
AUTHOR
Jean-François Alcover, May 24 2016
STATUS
approved