OFFSET
1,2
COMMENTS
Next term a(51)=0 if excess values A326499 are not allowed.
These are the numbers of graceful graphs with n edges and minimal vertices, up to a(50).
a(51) = 101666311328 is in this alternative sequence.
EXAMPLE
Sparse rulers (0,1,4,7,9) and (0,1,2,6,9) can each make 2 graceful graphs so a(9)=4.
CROSSREFS
KEYWORD
nonn,hard
AUTHOR
Ed Pegg Jr, Jun 04 2021
STATUS
approved