OFFSET
1,3
COMMENTS
PROG
(PARI) {a(n)=if(n<1, 0, SM=prod(i=0, n, matrix(n, n, r, c, if(r>=c, if((r+n-i)%(c+n-i)==0, moebius((r+n-i)/(c+n-i)), 0)))); U=SM*vector(n, i, 1)~; V=SM*vector(n, i, if(i==1, 1, 0))~; return(Vec(Ser(U)/Ser(V))[n]))}
CROSSREFS
KEYWORD
nonn
AUTHOR
Wouter Meeussen and Paul D. Hanna, Feb 28 2006
STATUS
approved