OFFSET
1,2
COMMENTS
Inspired by A272353.
All odd primes are obvious members.
Numbers k such that k == -1 (mod A000005(k)). Nonprime terms are listed in A354714. - Max Alekseyev, Jun 04 2022
63 is the least number that is not in this sequence but is a member of A187929.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
Claudia A. Spiro, How Often Does the Number of Divisors of an Integer Divide Its Successor?, J. London Math. Soc. (1985) s2-31 (1): 30-40.
EXAMPLE
15 is a term because A000005(15) = 4 divides 15+1 = 16.
MATHEMATICA
Select[Range@167, Mod[#+1, DivisorSigma[0, #]] == 0 &] (* Giovanni Resta, May 21 2016 *)
PROG
(PARI) lista(nn) = {for(n=1, nn, if((n+1) % numdiv(n) == 0, print1(n, ", "))); }
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, May 11 2016
STATUS
approved