A165766 Number of tatami-free rooms of size 2n.

0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 0, 2, 0, 0, 1, 0, 1, 0

Offset

1,99

Comments

Number of pairs (r,c) such that r<=c, r*c=2n and A068920(r,c)=0.

A165632 lists twice the indices of nonzero terms, i.e. A165632 = { 2n | a(n)=0 }.

Links

Table of n, a(n) for n=1..105.

Crossrefs

Sequence in context: A111373 A336757 A116376 * A102082 A358434 A030199

Adjacent sequences: A165763 A165764 A165765 * A165767 A165768 A165769

Keyword

nonn

Author

M. F. Hasler, Sep 26 2009

Status

approved