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a(n) = (1/s(1) + 1/s(2) + ... + 1/s(n+1)) * LCM{1, 2, ..., n}, where s(k) = LCM{1,2,...,k}/k = A002944(k).
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%I #17 Sep 04 2019 10:43:23

%S 1,2,5,17,35,181,182,1278,2559,7687,7688,84580,84581,1099567,1099582,

%T 1099590,2199181,37386095,37386096,710335844,710335865,710335887,

%U 710335888,16337725448,16337725453,81688627291,81688627300,245065881928,245065881929

%N a(n) = (1/s(1) + 1/s(2) + ... + 1/s(n+1)) * LCM{1, 2, ..., n}, where s(k) = LCM{1,2,...,k}/k = A002944(k).

%F a(n) = A003418(n) * Sum_{k=1..n+1} 1/A002944(k). - _Sean A. Irvine_, Sep 04 2019

%e n=4: LCM{1,2,3,4} = 12, so a(4) = 12*(1/1 + 1/1 + 1/2 + 1/3 + 1/12) = 12*35/12 = 35. - _N. J. A. Sloane_, Sep 04 2019

%o (PARI) s(n) = lcm([1..n])/n; \\ A002944

%o a(n) = lcm([1..n])*sum(k=1, n+1, 1/s(k)); \\ _Michel Marcus_, Sep 04 2019

%Y Cf. A003418, A002944, A025527.

%K nonn

%O 0,2

%A _Clark Kimberling_

%E Name improved by _Sean A. Irvine_, Sep 04 2019 and _N. J. A. Sloane_, Sep 04 2019