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 A049791 a(n) = Sum_{k=1..n} T(n,k), array T as in A049790. 7

%I #11 Sep 08 2022 08:44:58

%S 1,5,14,30,54,91,137,202,280,380,492,644,799,994,1212,1471,1735,2071,

%T 2400,2811,3232,3709,4190,4804,5380,6046,6739,7535,8297,9246,10115,

%U 11153,12184,13320,14458,15839,17074,18493,19931,21583,23100,24942,26609,28564,30517,32593,34585,37048,39231,41735,44187,46911

%N a(n) = Sum_{k=1..n} T(n,k), array T as in A049790.

%H G. C. Greubel, <a href="/A049791/b049791.txt">Table of n, a(n) for n = 1..1000</a>

%p seq( add(add(floor(n/floor(k/j)), j=1..k), k=1..n), n=1..60); # _G. C. Greubel_, Dec 10 2019

%t Table[Sum[Sum[Floor[n/Floor[k/j]], {j, k}], {k, n}], {n, 1, 60}] (* _G. C. Greubel_, Dec 10 2019 *)

%o (PARI) a(n) = sum(k=1,n, sum(j=1,k, n\(k\j) ));

%o vector(60, n, a(n)) \\ _G. C. Greubel_, Dec 10 2019

%o (Magma) [ &+[(&+[Floor(n/Floor(k/j)): j in [1..k]]): k in [1..n]] n in [1..60]]; // _G. C. Greubel_, Dec 10 2019

%o (Sage) [sum(sum(floor(n/floor(k/j)) for j in (1..k)) for k in (1..n)) for n in (1..60)] # _G. C. Greubel_, Dec 10 2019

%o (GAP) List([1..60], n-> Sum([1..n], k-> Sum([1..k], j-> Int(n/Int(k/j)) ))); # _G. C. Greubel_, Dec 10 2019

%Y Cf. A049790, A049792, A049793, A049794, A049795, A049796.

%K nonn

%O 1,2

%A _Clark Kimberling_

%E Terms a(40) onward added by _G. C. Greubel_, Dec 10 2019

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Last modified June 21 19:43 EDT 2024. Contains 373558 sequences. (Running on oeis4.)