A076484 Balanced numbers k such that 2*k is not a balanced number (k is in A020492, 2*k is not).

2, 12, 14, 30, 42, 56, 78, 140, 168, 190, 248, 264, 270, 418, 570, 594, 616, 630, 714, 744, 812, 840, 910, 1240, 1254, 1672, 1848, 2214, 2376, 2436, 2580, 2730, 3080, 3596, 3720, 3828, 3956, 4064, 4180, 4522, 4674, 5016, 5278, 5396, 5544, 6426, 6678

Offset

1,1

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000 (calculated using data from Jud McCranie)

Formula

sigma(k)/phi(k) is integer, sigma(2*k)/phi(2*k) is not.

Example

k = 12, 2*k = 24: sigma(12)/phi(12) = 28/4 = 7, while sigma(24)/phi(24) = 60/8 = 15/2.

Crossrefs

Cf. A020492, A000203, A000010, A076375, A076376, A076377.

Sequence in context: A073598 A232768 A022368 * A259128 A280942 A270119

Adjacent sequences: A076481 A076482 A076483 * A076485 A076486 A076487

Keyword

nonn

Author

Labos Elemer, Oct 15 2002

Status

approved