A345892 a(n) = n + (n - 1) * (n - phi(n)).
1, 3, 5, 10, 9, 26, 13, 36, 33, 64, 21, 100, 25, 118, 113, 136, 33, 222, 37, 248, 201, 274, 45, 392, 145, 376, 261, 460, 57, 668, 61, 528, 449, 628, 409, 876, 73, 778, 609, 976, 81, 1272, 85, 1076, 969, 1126, 93, 1552, 385, 1520, 1001, 1480, 105, 1962, 865, 1816, 1233, 1768
Offset: 1
Keywords
Programs
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Mathematica
Table[n + (n - 1)*(n - EulerPhi[n]), {n, 50}]
Formula
a(n) = Sum_{k=1..n} n^(1 - floor(1/gcd(n,k))).
Comments