Number of zero-sum -3..3 arrays of n elements with first and second differences also in -3..3.
A201868
Number of zero-sum -3..3 arrays of n elements with first and second differences also in -3..3.
Terms
- a(0) =1a(1) =3a(2) =15a(3) =45a(4) =169a(5) =643a(6) =2509a(7) =10129a(8) =41031a(9) =166337a(10) =678169a(11) =2772981a(12) =11365437a(13) =46717997a(14) =192513137a(15) =795049313a(16) =3289962901a(17) =13637608037a(18) =56617168555a(19) =235369429109a(20) =979676940333
External references
- oeis: A201868