OFFSET
0,2
COMMENTS
This is the fourth (k=3) column sequence in triangle A094645 without leading zeros.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..445
FORMULA
a(n) = abs(Stirling1(n+2,2)) - abs(Stirling1(n+2,3)), with the unsigned Stirling1 numbers abs(Stirling1(n,k)) = A132393(n,k).
E.g.f.: (1/2)*(2-log(1-x)^2)/(1-x)^2 (from differentiating three times (1-x)*((-log(1-x))^3)/3!).
MATHEMATICA
Table[Abs[StirlingS1[n+2, 2]]-Abs[StirlingS1[n+2, 3]], {n, 0, 20}] (* Harvey P. Dale, May 21 2015 *)
PROG
(PARI) a(n)=abs(stirling(n+2, 2))-abs(stirling(n+2, 3)) \\ Charles R Greathouse IV, Jun 27 2011
(Magma) [Abs(StirlingFirst(n+2, 2)) - Abs(StirlingFirst(n+2, 3)): n in [0..30]]; // G. C. Greubel, Jan 13 2018
CROSSREFS
KEYWORD
sign,easy
AUTHOR
Wolfdieter Lang, Jun 21 2011
STATUS
approved