Number of permutations of 1..n with all sums of 2 through 4 adjacent terms respectively unique.
A147726
Number of permutations of 1..n with all sums of 2 through 4 adjacent terms respectively unique.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =16a(4) =54a(5) =232a(6) =936a(7) =3880a(8) =17302a(9) =81584a(10) =425550a(11) =2332858a(12) =13639774a(13) =84416970a(14) =555549406a(15) =3834425860a(16) =27937916790
External references
- oeis: A147726