A385147 a(n) = Sum_{i=1..n} 2^phi(i), where phi=A000010.
2, 4, 8, 12, 28, 32, 96, 112, 176, 192, 1216, 1232, 5328, 5392, 5648, 5904, 71440, 71504, 333648, 333904, 338000, 339024, 4533328, 4533584, 5582160, 5586256, 5848400, 5852496, 274287952, 274288208, 1348030032, 1348095568, 1349144144, 1349209680, 1365986896, 1365990992
Offset: 1
Programs
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Mathematica
Accumulate[Table[2^EulerPhi[n], {n, 1, 36}]] (* Amiram Eldar, Jun 28 2025 *) -
PARI
a(n) = sum(i=1, n, 2^eulerphi(i)); \\ Michel Marcus, Jun 27 2025
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Python
from sympy import totient a = 0 terms = [] for i in range(1, 36): a += 2 ** totient(i) terms.append(str(a)) print(", ".join(terms))