Number of 3 X 3 0..n arrays with rows and columns in lexicographically nondecreasing order.

A229796

Number of 3 X 3 0..n arrays with rows and columns in lexicographically nondecreasing order.

Terms

    a(0) =45a(1) =1169a(2) =14178a(3) =102251a(4) =520017a(5) =2066505a(6) =6842284a(7) =19692165a(8) =50724037a(9) =119421753a(10) =261015470a(11) =535936479a(12) =1043365337a(13) =1940082033a(14) =3466044984a(15) =5978361865a(16) =9995569629a(17) =16254413569a(18) =25781605914a(19) =39983353235a(20) =60755768865a(21) =90619631609

External references