OFFSET
1,1
COMMENTS
Divisors of triangular number k = 120 can be partitioned into three disjoint sets whose sums are all sigma(k)/3 and this value is triangular numbers (=120). Are there other such triangular numbers?
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..398
EXAMPLE
Triangular number 780 is in sequence because sigma(780)/3 = 784 = 4+780 = 2+5+6+10+12+13+15+20+26+30+39+52+60+65+78+156+195 = 1+3+130+260+390 (summands are all divisors of 780).
CROSSREFS
KEYWORD
nonn
AUTHOR
Jaroslav Krizek, Feb 03 2012
STATUS
approved