A174172 Partials sums of A001694.
1, 5, 13, 22, 38, 63, 90, 122, 158, 207, 271, 343, 424, 524, 632, 753, 878, 1006, 1150, 1319, 1515, 1715, 1931, 2156, 2399, 2655, 2943, 3232, 3556, 3899, 4260, 4652, 5052, 5484, 5925, 6409, 6909, 7421, 7950, 8526, 9151, 9799, 10474, 11150, 11879, 12663
Offset: 1
Keywords
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
- Rafael Jakimczuk, The kernel of powerful numbers, International Mathematical Forum, Vol. 12, No. 15 (2017), pp. 721-730, Theorem 2.7, p. 729.
Programs
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Mathematica
Accumulate @ Select[Range[1000], # == 1 || Min[FactorInteger[#][[;; , 2]]] > 1 &] (* Amiram Eldar, Jan 30 2023 *)
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PARI
lista(kmax) = {my(s = 0); for(k = 1, kmax, if(k==1 || vecmin(factor(k)[, 2]) > 1, s += k; print1(s, ", ")));} \\ Amiram Eldar, May 13 2023
Formula
a(n) = Sum_{i=1..n} A001694(i).
a(n) ~ (zeta(3)^2/(3*zeta(3/2)^2)) * n^3. - Amiram Eldar, Jan 30 2023
a(n) = c * A001694(n)^(3/2) + o(A001694(n)^(3/2)), where c = zeta(3/2)/(3*zeta(3)) = 0.7244181041... (Jakimczuk, 2017). - Amiram Eldar, May 13 2023