Number of -2..2 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.
A200051
Number of -2..2 arrays x(0..n-1) of n elements with zero sum and elements alternately strictly increasing and strictly decreasing.
Terms
- a(0) =1a(1) =4a(2) =10a(3) =26a(4) =68a(5) =178a(6) =472a(7) =1276a(8) =3462a(9) =9496a(10) =26024a(11) =71956a(12) =198740a(13) =552814a(14) =1535556a(15) =4290252a(16) =11968194a(17) =33553214a(18) =93917400a(19) =264020106a(20) =741024426a(21) =2087799972a(22) =5872999754a(23) =16577458520a(24) =46720454112a(25) =132081262316a(26) =372843051320
External references
- oeis: A200051