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%I #16 Jul 14 2015 03:36:19
%S 1,5,7,17,11,38,15,49,34,60,23,132,27,82,82,129,35,191,39,207,112,126,
%T 47,384,86,148,142,283,59,469,63,321,172,192,172,666,75,214,202,597,
%U 83,640,87,435,403,258,95,1016,162,485,262,511,107,812,264,813,292,324
%N a(n) = Sum_{i|n, j|n, j >= i} j.
%H Harry J. Smith, <a href="/A064944/b064944.txt">Table of n, a(n) for n=1..1000</a>
%F a(n) = Sum_{i=1..tau(n)} i*d_i, where {d_i}, i=1..tau(n) is the increasing sequence of divisors of n.
%F a(n) = Sum_{i=1..A000005(n)} i*A027750(n, i). - _Michel Marcus_, Jun 10 2015
%e 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.
%p with(numtheory): seq(add(i*sort(convert(divisors(n),'list'))[i],i=1..tau(n)), n=1..200);
%o (PARI) { for (n=1, 1000, d=divisors(n); a=sum(i=1, length(d), i*d[i]); write("b064944.txt", n, " ", a) ) } \\ _Harry J. Smith_, Sep 30 2009
%o (Haskell)
%o a064944 = sum . zipWith (*) [1..] . a027750_row'
%o -- _Reinhard Zumkeller_, Jul 14 2015
%Y Cf. A000005, A060640, A064945.
%Y Cf. A027750.
%K nonn
%O 1,2
%A _Vladeta Jovovic_, Oct 28 2001
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