|
%I #11 Dec 31 2021 21:03:38
%S 1,3,6,262,267,8043,8050,68719484786,68720016227,68730016227,
%T 68730016238,184884327625052654,184884327625052667,184884348286099451,
%U 184884350848990076,340282366920938463463559491782617201532,340282366920938463463559491782617201549,340282366921167931715454621189757074317
%N a(n) = Sum_{k=1..n} k^(k'), where ' is the arithmetic derivative.
%e a(4) = 262; a(4) = Sum_{k=1..4} k^(k') = 1^(1') + 2^(2') + 3^(3') + 4^(4') = 1^0 + 2^1 + 3^1 + 4^4 = 262.
%p a:= n-> add(k^(k*add(i[2]/i[1], i=ifactors(k)[2])), k=1..n):
%p seq(a(n), n=1..18); # _Alois P. Heinz_, Oct 14 2021
%t Accumulate@ Array[#^If[# < 2, 0, # Total[#2/#1 & @@@ FactorInteger[#]]] &, 18] (* _Michael De Vlieger_, Oct 14 2021 *)
%Y Cf. A001923, A003415.
%K nonn
%O 1,2
%A _Wesley Ivan Hurt_, Oct 14 2021
|
