A006349 Related to series-parallel networks.

1, 5, 13, 45, 121, 413, 1261, 4221, 13801, 46365, 155497, 527613, 1792805, 6126293, 20986153, 72121853, 248396793, 857416949, 2964896877, 10269596445, 35622421561, 123728022269, 430254861945, 1497796774077, 5219231003621

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

References

• Z. A. Lomnicki, Two-terminal series-parallel networks, Adv. Appl. Prob., 4 (1972), 109-150.
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Cf. A000084, A006350, A058351, A058352, A058353, A000669.

Formula

A058352(n) + n*A000084(n).