|
%I #13 Sep 06 2019 10:58:32
%S 0,0,0,64,5120,450560,56197120,10877927424,3407830056960,
%T 1765179884830720,1528596578057584640,2225354662890778394624,
%U 5460264388115266042593280,22602991882128566753395998720,157891665026904821204431467970560
%N Number of 4-colored labeled graphs with n nodes.
%D F. Harary and E. M. Palmer, Graphical Enumeration, Academic Press, NY, 1973, p. 18, Table 1.5.1.
%H Andrew Howroyd, <a href="/A058874/b058874.txt">Table of n, a(n) for n = 1..80</a>
%t m = 16;
%t CoefficientList[Sum[x^j*j!*2^Binomial[j, 2], {j, 1, m}] + O[x]^n, x]* CoefficientList[(Sum[x^j/(j!*2^Binomial[j, 2]), {j, 1, n}] + O[x]^m)^4/24 + O[x]^m, x] // Rest (* _Jean-François Alcover_, Sep 06 2019, from PARI *)
%o (PARI) seq(n)={Vec(serconvol(sum(j=1, n, x^j*j!*2^binomial(j,2)) + O(x*x^n), (sum(j=1, n, x^j/(j!*2^binomial(j,2))) + O(x*x^n))^4)/24, -n)} \\ _Andrew Howroyd_, Nov 30 2018
%Y A diagonal of A058843.
%Y Equals 64 * A006202.
%K nonn
%O 1,4
%A _N. J. A. Sloane_, Jan 07 2001
|
