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A338647
a(n) = Sum_{k=1..n} 2^(k/gcd(n,k) - 1).
0
1, 2, 4, 7, 16, 22, 64, 92, 223, 342, 1024, 1132, 4096, 5462, 13534, 21937, 65536, 70978, 262144, 333472, 890590, 1398102, 4194304, 4528402, 16236031, 22369622, 57522106, 88435312, 268435456, 272976502, 1073741824, 1431677702, 3679303390, 5726623062, 16490405374, 18543422953
OFFSET
1,2
FORMULA
a(n) = Sum_{d|n} A054432(d).
MATHEMATICA
Table[Sum[2^(k/GCD[n, k] - 1), {k, 1, n}], {n, 1, 36}]
PROG
(PARI) a(n) = sum(k=1, n, 2^(k/gcd(n, k) - 1)); \\ Michel Marcus, Apr 22 2021
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Apr 22 2021
STATUS
approved