OFFSET
2,1
COMMENTS
An occurrence of a ranpp (xy;z) in a matrix A=(a(i,j)) is a triple (a(i1,j1), a(i1,j2), a(i2,j1)) where i1<i2, j1<j2 and these elements are in the same relative order as those in the triple (x,y,z). In general, the number of m X n 0-1 matrices in question is given by (n+2)*2^(m-1)+2*m*(n-1)-2 for m>1 and n>1.
LINKS
Tanya Khovanova, Recursive Sequences
S. Kitaev, On multi-avoidance of right angled numbered polyomino patterns, Integers: Electronic Journal of Combinatorial Number Theory 4 (2004), A21, 20pp.
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(n) = 26*n + 20.
MATHEMATICA
Range[72, 7000, 26] (* Vladimir Joseph Stephan Orlovsky, Jul 13 2011 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Sergey Kitaev, Nov 12 2004
STATUS
approved