OFFSET
1,1
LINKS
Christian Sievers, Table of n, a(n) for n = 1..857
Eric Weisstein's World of Mathematics, Hanoi Graph.
Eric Weisstein's World of Mathematics, Minimum Dominating Set.
PROG
(PARI)
lista(n)={my(l=List([3]), t=[[0, 2], [1, 1], [1, 2], [2, 0], [2, 1], [2, 2]], s=[[1+O(x), 0, 0, 0], [0, 0, x+O(x^2)], [0, x^2+O(x^3)], [x^3+O(x^4)]]); for(k=2, n, s=vector(4, i, vector(5-i, j, sum(xy=1, #t, sum(xz=1, #t, sum(yz=1, #t, s[1+(i>1)+(t[xy][1]==2)+(t[xz][1]==2)][1+(j>3)+(t[xy][1]==1)+(t[xz][1]==1)]*s[1+(i>2)+(t[xy][2]==2)+(t[yz][1]==2)][1+(j>2)+(t[xy][2]==1)+(t[yz][1]==1)]*s[1+(i>3)+(t[xz][2]==2)+(t[yz][2]==2)][1+(j>1)+(t[xz][2]==1)+(t[yz][2]==1)]))))); s/=x^(valuation(vecsum(vector(4, i, vecsum(s[i]))))); listput(l, pollead([1, 3, 3, 1]*vectorv(4, i, s[i][5-i])))); l} \\ Christian Sievers, May 23 2025
CROSSREFS
KEYWORD
nonn
AUTHOR
Eric W. Weisstein, May 12 2025
EXTENSIONS
a(6) and beyond from Christian Sievers, May 23 2025
STATUS
approved
