OFFSET
1,2
LINKS
Antti Karttunen, Table of n, a(n) for n = 1..10000
MATHEMATICA
a140635[n_] := NestWhile[#+1&, 1, DivisorSigma[0, n]!=DivisorSigma[0, #]&]
a140635[{m_, n_}] := Map[a140635, Range[m, n]]
a140635[{1, 89}] (* Hartmut F. W. Hoft, Jun 13 2023 *)
PROG
(PARI) A140635(n) = { my(nd = numdiv(n)); for (i=1, n, if (numdiv(i) == nd, return (i))); }; \\ After A139770, Antti Karttunen, May 27 2017
(Python)
from sympy import divisor_count as d
def a(n):
x=d(n)
m=1
while True:
if d(m)==x: return m
else: m+=1 # Indranil Ghosh, May 27 2017
CROSSREFS
KEYWORD
nonn
AUTHOR
Max Alekseyev, May 19 2008
STATUS
approved