A345090 a(n) = Sum_{k=1..n} k^floor(1/gcd(k,2*n-k)).

1, 2, 3, 6, 7, 10, 13, 20, 19, 26, 31, 32, 43, 50, 43, 72, 73, 66, 91, 92, 81, 122, 133, 112, 139, 170, 139, 184, 211, 142, 241, 272, 193, 290, 239, 240, 343, 362, 267, 344, 421, 282, 463, 464, 305, 530, 553, 416, 541, 530, 451, 652, 703, 522, 595, 704, 561, 842, 871, 524, 931

Offset

1,2

Links

Table of n, a(n) for n=1..61.

Example

a(4) = Sum_{k=1..4} k^floor(1/gcd(k,2*4-k)) = 1^floor(1/gcd(1,7)) + 2^floor(1/gcd(2,6)) + 3^floor(1/gcd(3,5)) + 4^floor(1/gcd(4,4)) = 1^1 + 2^0 + 3^1 + 4^0 = 1 + 1 + 3 + 1 = 6.

Mathematica

Table[Sum[k^Floor[1/GCD[k, 2 n - k]], {k, n}], {n, 80}]

Crossrefs

Cf. A345091.

Sequence in context: A293392 A161336 A266536 * A059096 A257678 A351554

Adjacent sequences: A345087 A345088 A345089 * A345091 A345092 A345093

Keyword

nonn

Author

Wesley Ivan Hurt, Jun 07 2021

Status

approved