A006350 Related to series-parallel networks. (Formerly M4388)

0, 1, 7, 27, 101, 337, 1151, 3843, 12965, 43773, 148529, 505605, 1727771, 5920823, 20345445, 70073901, 241849929, 836230109, 2896104951, 10044664507, 34884102385, 121293088909, 422196245641, 1471030361069, 5130057477187, 17905427995239

Offset

1,3

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).

Links

Table of n, a(n) for n=1..26.

Formula

Sum_{k=1..n-1} A000084(k)*A006349(n-k), n >= 2.

Crossrefs

Cf. A000084, A006349, A058351, A058352, A058353, A000669.

Sequence in context: A305653 A282642 A185080 * A054485 A090856 A055917

Adjacent sequences: A006347 A006348 A006349 * A006351 A006352 A006353

Keyword

nonn,easy

Author

N. J. A. Sloane.

Status

approved