Number of arrangements of n+2 nonzero numbers x(i) in -2..2 with the sum of x(i)*x(i+1) equal to zero.
A188242
Number of arrangements of n+2 nonzero numbers x(i) in -2..2 with the sum of x(i)*x(i+1) equal to zero.
Terms
- a(0) =16a(1) =20a(2) =120a(3) =300a(4) =1284a(5) =4132a(6) =16272a(7) =57808a(8) =223308a(9) =828456a(10) =3193588a(11) =12106616a(12) =46777036a(13) =179484068a(14) =695670728a(15) =2689241588a(16) =10454975104a(17) =40616587968a(18) =158328346172a(19) =617266507080
External references
- oeis: A188242