A316113 a(n) is the least sum of a tuple containing n as an element where the denominator of the sum of reciprocals isn't divisible by any of the prime factors of n.

1, 4, 9, 10, 20, 11, 35, 22, 30, 22, 66, 22, 91, 37, 28, 46, 119, 32, 152, 31, 41, 68, 184, 37, 110, 106, 93, 53, 261, 51, 279, 94, 69, 121, 59, 60, 370, 192, 97, 64, 451, 54, 430, 94, 65, 186, 517, 74, 259, 112, 122, 97, 583, 95, 92, 92, 158, 263, 767, 77, 671

Offset

1,2

Links

Ray Chandler, Table of n, a(n) for n = 1..100

Example

a(12) = 22 because the tuple [3, 3, 4, 12] has the sum of reciprocals 1/3 + 1/3 + 1/4 + 1/12 = 1 of which the denominator is 1 and has no common prime factors with n = 12.
a(25) = 110 because the tuple [5, 5, 25, 25, 50] has the sum of reciprocals 1/5 + 1/5 + 1/25 + 1/25 + 1/50 = 1/2 of which the denominator is 2 and has no common prime factors with n = 25.

Crossrefs

Cf. A051908, A201644, A201646, A201647, A201648, A201649.

Sequence in context: A102837 A356417 A004631 * A336256 A245096 A352097

Adjacent sequences: A316110 A316111 A316112 * A316114 A316115 A316116

Keyword

nonn

Author

David A. Corneth, Jul 22 2018

Extensions

More terms from Ray Chandler, Oct 02 2018

Status

approved