For graphs G and H, let N(G,H) denote the number of unlabeled, not necessarily induced copies of H in G, and let NP(n,H)
Nearby in the stack
be the maximum of
N(G,H)
over all
n
-vertex planar graphs
G
. We prove that, for every fixed integer
m≥3
,
NP(n,C2m+1)=2m(mn)m+Om(nm−1/5).
Heath, Martin, and Wells reduced the determination of the leading term to a weighted optimization conjecture involving cycles and paths. We prove a stronger sharp cycle--path inequality for probability weights on the edges of a complete graph and characterize equality in their conjectured inequality. Together with their reduction lemma, this settles the conjecture and yields the formula above, including the stated error term. The cases
m≥5
are new; combined with the known results for
C3
and
C5
, this determines the leading term for every fixed odd cycle in planar graphs.