A147925 Number of permutations of floor(i*4/3), i=0..n-1, with all sums of two and three adjacent terms respectively unique.

1, 2, 6, 24, 74, 312, 1620, 7876, 44022, 307314, 2064562, 15229866, 132064084, 1095500280, 10006003984, 104500649736

Offset

1,2

Links

Table of n, a(n) for n=1..16.

Crossrefs

Sequence in context: A107761 A147943 A147934 * A147917 A147946 A147937

Adjacent sequences: A147922 A147923 A147924 * A147926 A147927 A147928

Keyword

nonn

Author

R. H. Hardin, Nov 17 2008

Status

approved