A077027 Number of simple integral graphs on n nodes.

1, 2, 3, 6, 10, 20, 33, 71, 121, 269, 492

Offset: 1

Author

Eric W. Weisstein, Oct 18 2002

Keywords

• nonn
• more

Comments

Generated at the suggestion of Ed Pegg Jr.

Links

• Eric Weisstein's World of Mathematics, Integral Graph

Crossrefs

Cf. A064731 (number of simple connected integral graphs).

Cf. A287154 (number of simple disconnected integral graphs).

Cf. A363065 (number of Laplacian integral graphs).

Formula

Euler transform of A064731. - Eric M. Schmidt, Mar 23 2015

a(n) = A287154(n) + A064731(n).

Extensions

a(1) corrected and a(10)-a(11) added (using A064731) by Eric M. Schmidt, Mar 23 2015