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A174030
Partial sums of A007694.
4
1, 3, 7, 13, 21, 33, 49, 67, 91, 123, 159, 207, 261, 325, 397, 493, 601, 729, 873, 1035, 1227, 1443, 1699, 1987, 2311, 2695, 3127, 3613, 4125, 4701, 5349, 6117, 6981, 7953, 8977, 10129, 11425, 12883, 14419, 16147, 18091, 20139, 22443, 25035, 27951, 31023
OFFSET
1,2
COMMENTS
Partial sums of numbers k such that phi(k) divides k.
LINKS
FORMULA
a(n) = Sum_{i=1..n} A007694(i).
a(n) = 2*A259823(n-1) + 1. - Amiram Eldar, Nov 05 2024
MATHEMATICA
Accumulate[Select[Range[5000], Divisible[#, EulerPhi[#]] &]] (* Amiram Eldar, Nov 05 2024 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Jonathan Vos Post, Mar 06 2010
STATUS
approved