OFFSET
0,4
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..500
Wikipedia, Pentomino
FORMULA
a(n) = Sum_{k>0} k * A247709(n,k).
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 23 2014
STATUS
approved