A058353 n*A000084(n).

1, 4, 12, 40, 120, 396, 1260, 4176, 13788, 46240, 155496, 527160, 1792804, 6125028, 20986020, 72117632, 248396792, 857402748, 2964896876, 10269550040, 35622420288, 123727866768, 430254861944, 1497796242288, 5219231003500

Offset: 1

Author

N. J. A. Sloane, Dec 16 2000

Keywords

• nonn

References

• Z. A. Lomnicki, Two-terminal series-parallel networks, Adv. Appl. Prob., 4 (1972), 109-150.

Crossrefs

Cf. A000084, A006349, A006350, A058351, A058352, A000669.