OFFSET
0,3
FORMULA
a(n) = factorial(n-floor(n/3))*fallfac(n+1-floor(n/3),floor(n/3)), where fallfac is falling factorial, A008279.
a(n) ~ n! * 2^(2*n+2-2*floor(n,3)/3) / 3^(n+1/2). - Vaclav Kotesovec, May 23 2015
MATHEMATICA
Table[Factorial[n-Floor[n/3]]*FactorialPower[n+1-Floor[n/3], Floor[n/3], 1], {n, 0, 20}]
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Ran Pan, May 23 2015
STATUS
approved