OFFSET
1,1
COMMENTS
All terms are odd; includes all odd primes.
The odd terms that are not primes are 27, 35, 39, 45, 55, 63, 77, 95, 99, 115, 119, 125, 135, 141, 147, 155, 171, .... What are these numbers?
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
MAPLE
S:= {}:
R:= NULL: count:= 0:
for n from 1 while count < 200 do
v:= min(numtheory:-divisors(n*(n+1)/2) minus S);
S:= S union {v};
if v = n+1 then R:= R, n+1; count:= count+1 fi;
od:
R; # Robert Israel, Jul 30 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Jul 27 2019
STATUS
approved
