Number of zero-sum -2..2 arrays of n elements with first and second differences also in -2..2.
A201867
Number of zero-sum -2..2 arrays of n elements with first and second differences also in -2..2.
Terms
- a(0) =1a(1) =3a(2) =5a(3) =19a(4) =45a(5) =129a(6) =345a(7) =1031a(8) =2969a(9) =8803a(10) =25791a(11) =76285a(12) =225047a(13) =667807a(14) =1984599a(15) =5918017a(16) =17672419a(17) =52880691a(18) =158447783a(19) =475463579a(20) =1428412619a(21) =4296219727a(22) =12934516047a(23) =38978330199a(24) =117561661847a(25) =354857238103
External references
- oeis: A201867