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 A342543 a(n) = Sum_{k=1..n} phi(gcd(k, n))^gcd(k, n). 4
 1, 2, 10, 19, 1028, 76, 279942, 65558, 10077718, 1049608, 100000000010, 16777334, 106993205379084, 78364444044, 35184372090920, 281474976776236, 295147905179352825872, 101559966746268, 708235345355337676357650, 1152921504607897676, 46005119909369702026044, 10000000000100000000020 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Seiichi Manyama, Table of n, a(n) for n = 1..388 FORMULA a(n) = Sum_{d|n} phi(n/d) * phi(d)^d. If p is prime, a(p) = p-1 + (p-1)^p. MATHEMATICA a[n_] := DivisorSum[n, EulerPhi[n/#] * EulerPhi[#]^# &]; Array[a, 20] (* Amiram Eldar, Mar 15 2021 *) PROG (PARI) a(n) = sum(k=1, n, eulerphi(gcd(k, n))^gcd(k, n)); (PARI) a(n) = sumdiv(n, d, eulerphi(n/d)*eulerphi(d)^d); CROSSREFS Cf. A000010, A029935, A342423, A342488, A342539, A342541, A342544. Sequence in context: A299577 A259096 A317859 * A342539 A346810 A347024 Adjacent sequences: A342540 A342541 A342542 * A342544 A342545 A342546 KEYWORD nonn AUTHOR Seiichi Manyama, Mar 15 2021 STATUS approved

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Last modified September 23 21:37 EDT 2023. Contains 365554 sequences. (Running on oeis4.)