A263338 Triangle read by rows: T(n,k) is the number of graphs with n vertices and Szeget index k.

1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 2, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 2, 1, 1, 0, 1, 2, 2, 0, 0, 1, 1, 2, 5, 1, 2, 2, 2, 0, 0, 0, 2, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 1, 2, 2, 2, 3, 4, 1, 0, 1, 1, 3, 5, 2, 2, 3, 2, 1, 2, 2, 6, 6, 2, 5, 7, 10, 5, 5, 2, 6, 6, 3, 2, 2

Offset

1,18

Comments

Row sums give A000088, n >= 1.

Links

Table of n, a(n) for n=1..100.

FindStat - Combinatorial Statistic Finder, The Szeged index of a graph.

Example

Triangle begins:
1,
1,1,
1,1,0,1,1,
1,1,1,1,1,0,1,0,1,2,1,0,0,0,0,0,1,
1,1,1,1,2,1,1,0,1,2,2,0,0,1,1,2,5,1,2,2,2,0,0,0,2,0,0,0,1,1,0,0,0,0,0,0,1,
...

Crossrefs

Cf. A000088.

Sequence in context: A025448 A015010 A016011 * A103522 A101108 A279280

Adjacent sequences: A263335 A263336 A263337 * A263339 A263340 A263341

Keyword

nonn,tabf

Author

Christian Stump, Oct 15 2015

Status

approved