OFFSET
0,8
COMMENTS
Partial sums of the rows of A136564.
LINKS
Andrew Howroyd, Table of n, a(n) for n = 0..1325
R. J. Mathar, Statistics on Small Graphs, arXiv:1709.09000 [math.CO] (2017) Table 79.
EXAMPLE
The array begins:
1, 1, 1, 1, 1, 1, 1, 1, 1, ...
0, 1, 2, 2, 2, 2, 2, 2, 2, ...
0, 1, 6, 10, 11, 11, 11, 11, 11, ...
0, 1, 10, 31, 47, 51, 52, 52, 52, ...
0, 1, 19, 90, 198, 269, 291, 295, 296, 296, ...
0, 1, 28, 222, 713, 1270, 1596, 1697, 1719, 1723, ...
0, 1, 44, 520, 2423, 5776, 8838, 10425, 10922, ...
0, 1, 60, 1090, 7388, 24032, 46384, ...
0, 1, 85, 2180, 21003, 93067, ...
0, 1, 110, 4090, ...
...
PROG
(PARI)
permcount(v) = {my(m=1, s=0, k=0, t); for(i=1, #v, t=v[i]; k=if(i>1&&t==v[i-1], k+1, 1); m*=t*k; s+=t); s!/m}
edges(v, t) = {prod(i=2, #v, prod(j=1, i-1, my(g=gcd(v[i], v[j])); t(v[i]*v[j]/g)^(2*g))) * prod(i=1, #v, t(v[i])^v[i])}
G(n, x)={my(s=0); forpart(p=n, s+=permcount(p)/edges(p, i->1-x^i)); s/n!}
T(n)={Mat(vector(n+1, k, Col(O(y*y^n) + G(k-1, y + O(y*y^n)))))}
{my(A=T(10)); for(n=1, #A, print(A[n, ]))} \\ Andrew Howroyd, Oct 22 2019
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Benoit Jubin, May 03 2008
EXTENSIONS
More terms from Vladeta Jovovic and Benoit Jubin, Sep 10 2008
STATUS
approved