A361282 Number of rank n+1 simple connected series-parallel matroids on [2n].

0, 1, 75, 9345, 1865745, 554479695, 231052877055, 128938132548225, 92986310399407425, 84250567868935042575, 93744545254140599193375, 125717783386887888296925825, 200041202339679732328342670625, 372688996228146502285257581079375, 803768398459351988653830600415029375

Offset

1,3

Links

Table of n, a(n) for n=1..15.

Luis Ferroni and Matt Larson, Kazhdan-Lusztig polynomials of braid matroids, arXiv:2303.02253 [math.CO], 2023.

Example

For n=2 the a(2) = 1 rank 3 simple connected series-parallel matroid on [4] is the uniform matroid of rank 3.

Prog

(PARI) a(n) = T(2*n)[2*n][n+1] \\ T(n) defined in A361355. - Andrew Howroyd, Mar 09 2023

Crossrefs

Cf. A034941, A361355.

Sequence in context: A248545 A114910 A294983 * A093275 A251242 A259464

Adjacent sequences: A361279 A361280 A361281 * A361283 A361284 A361285

Keyword

nonn

Author

Matt Larson, Mar 06 2023

Extensions

Terms a(10)-a(15) from Andrew Howroyd, Mar 09 2023

Status

approved