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A345313 a(n) = Sum_{p|n, p prime} (n/p)^lcm(p,n/p). 0

%I #7 Mar 23 2023 07:37:29

%S 0,1,1,4,1,793,1,256,27,9766649,1,16823872,1,678223089233,30531927032,

%T 16777216,1,150094635297045777,1,1109511627776,558545874543637210,

%U 81402749386839765307625,1,4722366491785745661952,3125,91733330193268616658466724873,387420489

%N a(n) = Sum_{p|n, p prime} (n/p)^lcm(p,n/p).

%C a(p) = Sum_{p|p} (p/p)^lcm(p,p/p) = 1^p = 1 for primes p.

%H <a href="/index/Lc#lcm">Index entries for sequences related to lcm's</a>

%e a(10) = Sum_{p|10} (10/p)^lcm(p,10/p) = 5^lcm(2,5) + 2^lcm(5,2) = 5^10 + 2^ 10 = 9766649.

%t Table[Sum[(n/k)^LCM[k, n/k] (PrimePi[k] - PrimePi[k - 1]) (1 - Ceiling[n/k] + Floor[n/k]), {k, n}], {n, 30}]

%K nonn

%O 1,4

%A _Wesley Ivan Hurt_, Jun 13 2021

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Last modified July 18 00:08 EDT 2024. Contains 374377 sequences. (Running on oeis4.)