OFFSET
1,3
REFERENCES
J. L. Gross and J. Yellen, eds., Handbook of Graph Theory, CRC Press, 2004; p. 521.
LINKS
G. C. Greubel, Table of n, a(n) for the first 25 rows, flattened
FORMULA
T(n,k) = binomial(n*(n-1), k). - Andrew Howroyd, Apr 19 2020
EXAMPLE
Triangle begins:
1
1 2 1
1 6 15 20 15 6 1
1 12 66 220 495 792 924 792 495 220 66 12 1
MATHEMATICA
Table[CoefficientList[Series[(1+x)^(2*Binomial[n, 2]), {x, 0, 2*Binomial[n, 2]}], x], {n, 6}] (* Geoffrey Critzer, Nov 12 2011 *)
PROG
(PARI) T(n, k)={binomial(n*(n-1), k)}
{for(n=1, 5, for(k=0, n*(n-1), print1(T(n, k), ", ")); print)} \\ Andrew Howroyd, Apr 19 2020
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
N. J. A. Sloane, Nov 15 2006
EXTENSIONS
More terms from Vladeta Jovovic, Nov 15 2006
STATUS
approved