A147907 Number of permutations of floor(i*9/8), i=0..n-1, with all sums of 2 through 4 adjacent terms respectively unique.

1, 2, 6, 16, 54, 232, 936, 3880, 23002, 127008, 751100, 4670780, 29781390, 193211704, 1334448490, 9604883174

Offset

1,2

Links

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

Crossrefs

Sequence in context: A147727 A147726 A147916 * A147634 A147899 A147949

Adjacent sequences: A147904 A147905 A147906 * A147908 A147909 A147910

Keyword

nonn

Author

R. H. Hardin, Nov 17 2008

Status

approved