A182463 Integers m arising from A068977.

1, 2, 5, 7, 9, 11, 13, 15, 15, 19, 21, 25, 25, 24, 31, 33, 39, 35, 43, 45, 49, 40, 55, 61, 63, 55, 69, 73, 75, 65, 56, 81, 85, 60, 75, 91, 99, 103, 105, 64, 109, 111, 115, 105, 88, 129, 133, 115, 139, 141, 84, 125, 104, 151, 153, 100, 159, 135

Offset

1,2

Comments

See A068977.

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) = A324503(A068977(n)). - Amiram Eldar, Feb 02 2025

Example

1 = 1, 2 = 1 + 2/tau(2), 5 = 1 + 2/tau(2) + 3/tau(3) + 6/tau(6), 7 = 1 + 2/tau(2) + 5/tau(5) + 10/tau(10), ....

Mathematica

Select[Table[Sum[k/DivisorSigma[0, k], {k, Divisors[n]}], {n, 1, 1000}], IntegerQ[#] &] (* Vaclav Kotesovec, Mar 22 2019 *)

Prog

(PARI) list(lim) = {my(s); for(k = 1, lim, s = sumdiv(k, d, d/numdiv(d)); if(denominator(s) == 1, print1(s, ", "))); } \\ Amiram Eldar, Feb 02 2025

Crossrefs

Cf. A068977, A324503, A324504.

Sequence in context: A256699 A247421 A007069 * A163985 A130773 A140139

Adjacent sequences: A182460 A182461 A182462 * A182464 A182465 A182466

Keyword

nonn,easy

Author

Naohiro Nomoto, Apr 30 2012

Status

approved