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A076484 n is balanced but 2n is not a balanced number: n is in A020492, 2n is not. 0
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..47.

FORMULA

sigma[n]/phi[n] is integer, sigma[2n]/phi[2n] is not

EXAMPLE

n=12,2n=24:sigma[12]/phi[12]=28/4=7, while sigma[24]/phi[24]=60/8=15/2

CROSSREFS

Cf. A020492, A000203, A000010, A076375-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

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Last modified August 22 00:43 EDT 2019. Contains 326169 sequences. (Running on oeis4.)