OFFSET
0,2
REFERENCES
I. P. Goulden and D. M. Jackson, Combinatorial Enumeration, Wiley, N.Y., 1983,(Problem 3.4.15).
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..100
EXAMPLE
There are 13 2 X 2 matrices over {0,1,2} with all row and column sums equal to 1 or 2, cf. A062154.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Vladeta Jovovic, Jun 06 2001
EXTENSIONS
Terms a(15) and beyond from Andrew Howroyd, Feb 03 2021
STATUS
approved