Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any element within a city block distance of two, and containing the value n(n+1)/2-3.
A212040
Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any element within a city block distance of two, and containing the value n(n+1)/2-3.
Terms
- a(0) =0a(1) =1a(2) =5a(3) =119a(4) =1310a(5) =7849a(6) =32696a(7) =107400a(8) =298404a(9) =731960a(10) =1630174a(11) =3361016a(12) =6505445a(13) =11945114a(14) =20974435a(15) =35441099a(16) =57919461a(17) =91921515a(18) =142150499a(19) =214802485a(20) =317921624a(21) =461815031
External references
- oeis: A212040