A263000 Triangle T(n,k) read by rows: T(n,k) is the number of graphs of length n with Wiener index k.

1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 2, 4, 4, 3, 3, 1, 1, 0, 1, 1, 1, 1, 2, 2, 1, 2, 3, 4, 3, 3, 2, 2, 4, 4, 4, 4, 3, 6, 9, 13, 17, 14, 11, 9, 10, 4, 6, 4, 3, 0, 2, 1, 0, 0, 1

Offset

1,17

Comments

Row sums give A000088, n >= 1. - Omar E. Pol, Oct 07 2015

Links

Table of n, a(n) for n=1..76.

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

Martin Knor, Riste Škrekovski, Aleksandra Tepeh, Mathematical aspects of Wiener index, arXiv:1510.00800 [math.CO], (3-October-2015)

Example

Triangle begins:
1,
1,1,
1,1,0,1,1,
1,1,1,1,1,0,1,1,2,1,1,
1,1,1,1,2,1,1,1,2,1,2,1,2,4,4,3,3,1,1,0,1,
1,1,1,2,2,1,2,3,4,3,3,2,2,4,4,4,4,3,6,9,13,17,14,11,9,10,4,6,4,3,0,2,1,0,0,1,
...

Crossrefs

Cf. A000088.

Sequence in context: A191515 A320001 A168201 * A075774 A367760 A195007

Adjacent sequences: A262997 A262998 A262999 * A263001 A263002 A263003

Keyword

nonn,tabf

Author

Christian Stump, Oct 07 2015

Status

approved