OFFSET
1,5
COMMENTS
Number of integers, m, such that 1<=m<=n and d_i(n)>d_i(m) for at least one index 1<=i<=Min(d(n),d(m)) where d_i(k) denotes the i-th smallest divisor of k and d(k) denotes the number of divisors of k.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
a(10) = 3 because A137849(10)=7. Also, there are 3 integers, 4, 6, and 8, whose divisors meet the criterion from the comment for n = 10 (the third smallest divisor of 4 is 4 and the third smallest divisor of 10 is 5; similarly 6 and 8 meet the criterion).
PROG
(Sage)
def a(n):
N=n.divisors()
count=0
for m in [1..n]:
M=m.divisors()
for i in range(min(len(N), len(M))):
if N[i]>M[i]:
count+=1
break
return count
[a(i) for i in [1..70]] # Tom Edgar, May 03 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
J. Lowell, May 03 2014
EXTENSIONS
More terms from Tom Edgar, May 03 2014
STATUS
approved