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A119434 Odd n such that 2*phi(n) < n. 3
105, 165, 195, 315, 495, 525, 585, 735, 825, 945, 975, 1155, 1365, 1485, 1575, 1755, 1785, 1815, 1995, 2145, 2205, 2415, 2475, 2535, 2625, 2805, 2835, 2925, 3003, 3045, 3135, 3255, 3315, 3465, 3675, 3705, 3795, 3885, 3927, 4095, 4125, 4305, 4389, 4455 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

COMMENTS

Obviously 2*phi(n) = n is impossible for odd n. Odd elements of A054741 and A119432. This is not the same as A036798. 684411 = 3*7*13*23*109 is in this sequence but not in A036798. (This is may not be the smallest such value.) The primitive elements of this sequence are A119433, excluding the initial 2.

FORMULA

A036798 UNION A118700. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 08 2007

CROSSREFS

Cf. A000010, A054741, A119432.

Sequence in context: A189936 A076762 A036798 * A091495 A046405 A128278

Adjacent sequences:  A119431 A119432 A119433 * A119435 A119436 A119437

KEYWORD

nonn

AUTHOR

Frank Adams-Watters (FrankTAW(AT)Netscape.net), May 19 2006

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Last modified February 17 23:58 EST 2012. Contains 206085 sequences.