OFFSET
0,5
FORMULA
Apart from first 3 rows, use the Pascal rule.
T(n, k) = C(n, k) + 2C(n-2, k-1). G.f.: (1+2x^2y) / [1-x(1+y)]. - Ralf Stephan, Jan 31 2005
EXAMPLE
1; 1 1; 1 4 1; 1 5 5 1; 1 6 10 6 1; ...
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
EXTENSIONS
More terms from Ben Baugher (s1191623(AT)cedarville.edu)
STATUS
approved