OFFSET
1,1
REFERENCES
Brualdi, Richard A. and Ryser, Herbert J., Combinatorial Matrix Theory, Cambridge NY (1991), Chapter 7.
LINKS
Indranil Ghosh, Table of n, a(n) for n = 1..446
Seok-Zun Song et al., Extremes of permanents of (0,1)-matrices, Lin. Algebra and its Applic. 373 (2003), pp. 197-210.
FORMULA
a(n) = (n+2)*a(n-1) + (n-2)*a(n-2), a(1)=4, a(2)=16
a(n) ~ exp(-1) * n! * n^3 / 6. - Vaclav Kotesovec, Nov 30 2017
MATHEMATICA
t={4, 16}; Do[AppendTo[t, (n+2)*t[[-1]]+(n-2)*t[[-2]]], {n, 3, 18}]; t (* Indranil Ghosh, Feb 21 2017 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Jaap Spies, Dec 13 2003
EXTENSIONS
Corrected by Jaap Spies, Jan 26 2004
STATUS
approved