OFFSET
0,6
LINKS
Dmitry Efimov, Determinants of generalized binary band matrices, arXiv:1702.05655 [math.RA], 2017.
FORMULA
a(n) = (A000271(n) + (-1)^(n-1) * floor((n-1)/2))/2.
MATHEMATICA
a[n_] := (Sum[(-1)^(n-k) k! Binomial[n+k, 2 k], {k, 0, n}] + (-1)^(n-1)* Floor[(n-1)/2])/2; Table[a[n], {n, 0, 23}] (* Jean-François Alcover, Feb 18 2019 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric M. Schmidt, Sep 28 2017
STATUS
approved