A147902 Number of permutations of floor(i*5/4), i=0..n-1, with all sums of 2 through 4 adjacent terms respectively unique.

1, 2, 6, 16, 74, 304, 1424, 6554, 36720, 207648, 1262922, 7739400, 57383696, 429424444, 3331954076, 26331934036

Offset

1,2

Links

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

Crossrefs

Sequence in context: A009367 A114249 A147910 * A147893 A147951 A147942

Adjacent sequences: A147899 A147900 A147901 * A147903 A147904 A147905

Keyword

nonn

Author

R. H. Hardin, Nov 17 2008

Status

approved