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A345091
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a(n) = Sum_{k=1..n} k^floor(1/gcd(n,k)).
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3
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1, 2, 4, 6, 11, 10, 22, 20, 30, 26, 56, 32, 79, 50, 67, 72, 137, 66, 172, 92, 135, 122, 254, 112, 255, 170, 252, 184, 407, 142, 466, 272, 343, 290, 431, 240, 667, 362, 483, 344, 821, 282, 904, 464, 561, 530, 1082, 416, 1036, 530, 835, 652, 1379, 522, 1115, 704, 1047, 842
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OFFSET
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1,2
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LINKS
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FORMULA
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If p is prime, a(p) = Sum_{k=1..p} k^floor(1/gcd(p,k)) = 1^1 + ... + (p-1)^1 + p^0 = p*(p-1)/2 + 1.
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EXAMPLE
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a(6) = Sum_{k=1..6} k^floor(1/gcd(6,k)) = 1^1 + 2^0 + 3^0 + 4^0 + 5^1 + 6^0 = 1 + 1 + 1 + 1 + 5 + 1 = 10.
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MATHEMATICA
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Table[Sum[k^Floor[1/GCD[n, k]], {k, n}], {n, 80}]
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PROG
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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