login
A036055
Number of cycles of the permutation created by length sorting on the partitions of n.
1
1, 2, 3, 4, 5, 6, 6, 5, 8, 7, 7, 8, 9, 9, 11, 10, 11, 11, 11, 11, 17, 14, 11, 13, 16, 11, 18, 17, 17, 13, 12, 19, 17, 17, 20, 13, 21, 14, 15, 15, 15, 13, 12, 13, 12, 24, 19, 27, 15, 19, 12, 21, 14, 12, 17, 16, 16, 18, 17, 20, 12, 18, 20, 17, 23, 14, 20, 20, 25
OFFSET
1,2
PROG
(PARI)
OrderCycs(v)={my(t=vector(#v), L=List()); for(i=1, #v, my(c=0, j=i); while(!t[j], t[j]=1; j=v[j]; c++); if(c, listput(L, c))); Vec(L)}
a(n)={my(u=vecsort([Vecsmall(Vecrev(p)) | p<-partitions(n)])); my(v=vecsort(u, (x, y)->lex(#x, #y), 1+4)); #OrderCycs(v)} \\ Andrew Howroyd, Sep 17 2019
CROSSREFS
KEYWORD
nonn
EXTENSIONS
a(31)-a(50) from Andrew Howroyd, Sep 17 2019
More terms from Sean A. Irvine, Oct 20 2020
STATUS
approved