OFFSET
1,2
COMMENTS
a(n) >= 1.
EXAMPLE
a(2) = 3; A094519(2) = 12 has divisors {1,2,3,4,6,12}. There are 3 divisor pairs, (d1,d2) such that (d1+d2) | 12 and where d1 < d2: (1,2), (1,3) and (2,4); so a(2) = 3.
a(3) = 2; A094519(3) = 18 has divisors {1,2,3,6,9,18}. There are 2 divisor pairs, (d1,d2) such that (d1+d2) | 18 and where d1 < d2: (1,2) and (3,6); so a(3) = 2.
a(4) = 1; A094519(4) = 20 has divisors {1,2,4,5,10,20}. There is 1 divisor pair, (d1,d2) such that (d1+d2) | 20 and where d1 < d2: (1,4). So a(4) = 1.
a(5) = 5; A094519(5) = 24 has divisors {1,2,3,4,6,8,12,24}. There are 5 divisor pairs, (d1,d2) such that (d1+d2) | 24 and where d1 < d2: (1,2), (1,3), (2,4), (2,6) and (4,8). So a(5) = 5.
CROSSREFS
KEYWORD
nonn
AUTHOR
Wesley Ivan Hurt, Aug 22 2020
STATUS
approved