OFFSET
0,4
COMMENTS
Also the number of permutations pi in S_n such that pi(i) + i != 2 (mod 3) for all i. - Peter Kagey, Jan 25 2021
MATHEMATICA
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 15 2012
EXTENSIONS
Typo in name corrected by Michel Marcus, Nov 11 2016
a(0) and a(23)-a(24) from Pontus von Brömssen, Jan 29 2021
STATUS
approved