A240801 - OEIS

A240801

Triangle read by rows: T(n,k) (n>=2, 0 <= k <= n-2) = number of possible topologies with n given vertices and n-k-2 Steiner points.

1, 1, 3, 3, 12, 12, 15, 75, 120, 60, 105, 630, 1350, 1200, 360, 945, 6615, 17640, 22050, 12600, 2520

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

2,3

LINKS

E. N. Gilbert and H. O. Pollak, Steiner minimal trees, SIAM J. Appl. Math. 16, (1968), pp. 1-29. See Table 1.

EXAMPLE

Triangle begins:

1, 3

3, 12, 12

15, 75, 120, 60

105, 630, 1350, 1200, 360

945, 6615, 17640, 22050, 12600, 2520

...

CROSSREFS

Row sums = A104653. A001710 and A001147 are diagonals.

KEYWORD

nonn,tabl,more

AUTHOR

STATUS

approved