Number of 0..2 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

A200880

Number of 0..2 arrays x(0..n+1) of n+2 elements without any interior element greater than both neighbors.

Terms

    a(0) =22a(1) =51a(2) =121a(3) =292a(4) =704a(5) =1691a(6) =4059a(7) =9749a(8) =23422a(9) =56268a(10) =135166a(11) =324692a(12) =779977a(13) =1873673a(14) =4500958a(15) =10812237a(16) =25973244a(17) =62393157a(18) =149881402a(19) =360046432a(20) =864906711a(21) =2077686532a(22) =4991036946a(23) =11989513056a(24) =28801314179a(25) =69186771332

External references