OFFSET
1,2
COMMENTS
The corresponding numbers of deficient divisors are 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 15, 16, 17, 18, 22, ...
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..120
EXAMPLE
2 is in the sequence since it is the least number with 2 deficient divisors, 1 and 2. The next number with more than 2 deficient divisors is 4, which has 3 deficient divisors, 1, 2, and 4.
MATHEMATICA
s[n_] := Count[Divisors[n], _?(DivisorSigma[1, #] < 2*# &)]; sm = -1; seq = {}; Do[s1 = s[n]; If[s1 > sm, sm = s1; AppendTo[seq, n]], {n, 1, 10^6}]; seq
Module[{nn=800000, lst}, lst=Table[{n, Count[Divisors[n], _?(DivisorSigma[1, #]<2#&)]}, {n, nn}]; DeleteDuplicates[lst, GreaterEqual[#1[[2]], #2[[2]]]&]][[;; , 1]] (* Harvey P. Dale, May 06 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, Jun 13 2020
STATUS
approved