OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
FORMULA
a(n) = Sum_{i=1..tau(n)} (2*i-1)*d_i, where {d_i}, i=1..tau(n), is increasing sequence of divisors of n.
EXAMPLE
a(6) = dot_product(1,3,5,7)*(1,2,3,6) = 1*1 + 3*2 + 5*3 + 7*6 = 64.
MAPLE
with(numtheory): seq(add((2*i-1)*sort(convert(divisors(n), 'list'))[i], i=1..tau(n)), n=1..200);
PROG
(PARI) { for (n=1, 1000, d=divisors(n); a=sum(i=1, length(d), (2*i - 1)*d[i]); write("b064948.txt", n, " ", a) ) } \\ Harry J. Smith, Oct 01 2009
CROSSREFS
KEYWORD
nonn
AUTHOR
Vladeta Jovovic, Oct 28 2001
STATUS
approved