A035928(n) = my (b=binary(n)); (n+1)*2^#b-fromdigits(Vecrev(b),2)-1 a = vector(10 000) u = 1 for (n=1, oo, m=A035928(n); fordiv (m, d, if (d>#a, break, a[d]==0, a[d]=m)); while (a[u], print (u " " a[u]/u); if (u++>#a, break (2)))) quit