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 A120110 Diagonal sums of number triangle A120108. 2

%I

%S 1,2,7,15,67,92,461,1065,3016,3956,29478,42231,379107,547556,603421,

%T 991923,12709228,18540622,241033695,352271227,389226278,407797820,

%U 5532937710,8097345425,30368363481,41503874738,98701094676,127342427241

%N Diagonal sums of number triangle A120108.

%H Muniru A Asiru, <a href="/A120110/b120110.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) = Sum_{k=0..floor(n/2)} lcm(1,..,n-k+1)/lcm(1,..,k+1).

%o (GAP) List([0..30],n->Sum([0..Int(n/2)],k->Lcm(List([1..n-k+1],i->i))/Lcm(List([1..k+1],i->i)))); # _Muniru A Asiru_, Mar 04 2019

%o (PARI) a(n) = sum(k=0, n\2, lcm([1..n-k+1])/lcm([1..k+1])); \\ _Michel Marcus_, Mar 04 2019

%Y Cf. A120108.

%K easy,nonn

%O 0,2

%A _Paul Barry_, Jun 09 2006

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Last modified February 27 07:02 EST 2020. Contains 332299 sequences. (Running on oeis4.)