Number of -n..n circular arrays x(0..8) of 9 elements with zero sums of x(i) and x(i)*x((i+1) mod 9).

A202011

Number of -n..n circular arrays x(0..8) of 9 elements with zero sums of x(i) and x(i)*x((i+1) mod 9).

Terms

    a(0) =577a(1) =15751a(2) =101395a(3) =490879a(4) =1519417a(5) =4460689a(6) =9882793a(7) =21851983a(8) =40831435a(9) =77490037a(10) =129389941a(11) =219474487a(12) =336880639a(13) =536126239a(14) =777338533a(15) =1152674479a(16) =1605065239a(17) =2301180355a(18) =3090983005a(19) =4236736987a(20) =5528432323a(21) =7416995779

External references