A147934 Number of permutations of floor(i*4/3), i=0..n-1, with all sums of 2 through 4 adjacent terms respectively unique.

1, 2, 6, 24, 74, 312, 1620, 7876, 41114, 262142, 1640026, 10906856, 84761678, 627751836, 5070873342, 46757075664

Offset

1,2

Links

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

Crossrefs

Sequence in context: A173844 A107761 A147943 * A147925 A147917 A147946

Adjacent sequences: A147931 A147932 A147933 * A147935 A147936 A147937

Keyword

nonn

Author

R. H. Hardin, Nov 17 2008

Status

approved