The On-Line Encyclopedia of Integer Sequences (OEIS)

A301731 revision #5

A301731

Triangle read by rows: T(n,m) = one-half of number of embeddings of the n-wheel with k = n+1-2m regions (n >= 1, 0 <= m <= floor(n/2)).

1, 1, 1, 1, 7, 1, 29, 18, 1, 95, 288, 1, 275, 2484, 1080, 1, 742, 15589, 29748

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OFFSET

1,5

LINKS

Yichao Chen et al., On the genus distribution of wheels ..., Discrete Math., 341 (2018), 934-935.

FORMULA

Theorem 3.4 of Chen et al. (2018) gives a formula.

EXAMPLE

Triangle begins:

1,1,

1,7,

1,29,18,

1,95,288,

1,275,2484,1080,

1,742,15589,29748,

...

CROSSREFS

KEYWORD

nonn,tabf,more,new

AUTHOR

STATUS

approved