OFFSET
0,5
LINKS
Robert Israel, Table of n, a(n) for n = 0..898
FORMULA
From Robert Israel, Jan 11 2018: (Start)
a(2*k) = e*Gamma(k+1,1) - k! - 1.
a(2*k+1) = e*Gamma(k+2,1) - (k+1)! - k - 2. (End)
MAPLE
seq(op(simplify([exp(1)*GAMMA(k+1, 1)-k!-1, exp(1)*GAMMA(k+2, 1)-(k+1)!-k-2])), k=0..20); # Robert Israel, Jan 11 2018
MATHEMATICA
FoldList[If[OddQ@ #2, #1 ((#2 + 1)/2), #1 + #2/2] &, -1, Range@ 31] (* Michael De Vlieger, Jan 11 2018 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Vladeta Jovovic, Apr 25 2003
STATUS
approved