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%I #14 Oct 09 2021 01:10:41
%S 0,3,8,14,20,27,35,41,50,58,66,74,84,91,101,111,119,127,140,146,158,
%T 168,176,186,198,207,217,227,239,247,261,267,280,292,300,312,326,332,
%U 344,356,368,377,391,399,411,425,435,443,459,467,482,492,502,514,528
%N a(n) = Sum_{k = 1..2n} floor(2n/k).
%C The sequence A006218 : Sum_{i=1..n} floor(n/i) = Sum_{i=1..n} sigma_0(i). Sigma_0(i) is A000005. Sequences of the type : Sum_{i=1..f(n)} floor(f(n)/i)= Sum_{i=1..f(n)} sigma_0(i). This sequence a(n)= A006218(2*n). [_Ctibor O. Zizka_, Mar 21 2009]
%C For n > 0: row sums of the triangle in A013942. - _Reinhard Zumkeller_, Jun 04 2013
%H Reinhard Zumkeller, <a href="/A062550/b062550.txt">Table of n, a(n) for n = 0..10000</a>
%F a(n) = A006218(2n) = A056549(n)+A006218(n) = a(n-1)+A000005(2n-1)+A000005(2n)
%t Table[Total[Floor[2*n/Range[2*n]]], {n, 0, 100}] (* _T. D. Noe_, Jun 12 2013 *)
%o (Haskell)
%o a062550 0 = 0
%o a062550 n = sum $ a013942_row n -- _Reinhard Zumkeller_, Jun 04 2013
%o (Python)
%o from math import isqrt
%o def A062550(n): return (lambda m: 2*sum(2*n//k for k in range(1, m+1))-m*m)(isqrt(2*n)) # _Chai Wah Wu_, Oct 09 2021
%o (PARI) a(n) = sum(k=1, 2*n, (2*n)\k); \\ _Michel Marcus_, Oct 09 2021
%Y Cf. A013942, A156745, A085831, A153816, A153817, A153876.
%K nonn
%O 0,2
%A _Henry Bottomley_, Jun 26 2001
%E Data corrected for n > 30 by _Reinhard Zumkeller_, Jun 04 2013
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