|
Search: id:A064944
|
|
|
| A064944 |
|
Sum_{i|n, j|n, j >= i} j. |
|
+0
1
|
|
| 1, 5, 7, 17, 11, 38, 15, 49, 34, 60, 23, 132, 27, 82, 82, 129, 35, 191, 39, 207, 112, 126, 47, 384, 86, 148, 142, 283, 59, 469, 63, 321, 172, 192, 172, 666, 75, 214, 202, 597, 83, 640, 87, 435, 403, 258, 95, 1016, 162, 485, 262, 511, 107, 812, 264, 813, 292, 324
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
LINKS
|
Harry J. Smith, Table of n, a(n) for n=1,...,1000
|
|
FORMULA
|
a(n) = Sum_{i=1..tau(n)} i*d_i, where {d_i}, i=1..tau(n) is increasing sequence of divisors of n.
|
|
EXAMPLE
|
a(6) = max(1,1)+max(1,2)+max(1,3)+max(1,6)+max(2,2)+max(2,3)+max(2,6)+max(3,3)+max(3,6)+max(6,6)=38, or a(6) = dot_product(1,2,3,4)*(1,2,3,6)=1*1+2*2+3*3+4*6=38.
|
|
MAPLE
|
with(numtheory): seq(add(i*sort(convert(divisors(n), 'list'))[i], i=1..tau(n)), n=1..200);
|
|
PROGRAM
|
(PARI) { for (n=1, 1000, d=divisors(n); a=sum(i=1, length(d), i*d[i]); write("b064944.txt", n, " ", a) ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Sep 30 2009]
|
|
CROSSREFS
|
Cf. A000005, A060640.
Sequence in context: A106506 A029649 A060640 this_sequence A070372 A082818 A075089
Adjacent sequences: A064941 A064942 A064943 this_sequence A064945 A064946 A064947
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Vladeta Jovovic (vladeta(AT)eunet.rs), Oct 28 2001
|
|
|
Search completed in 0.002 seconds
|
