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A070287 Numbers n such that the equation lcm(sigma(x),phi(x))=n has solutions. 0
1, 3, 4, 12, 14, 24, 28, 36, 48, 60, 72, 78, 84, 96, 120, 144, 168, 180, 192, 240, 248, 264, 288, 312, 336, 360, 420, 432, 480, 496, 576, 620, 672, 684, 720, 780, 792, 798, 840, 864, 924, 936, 960, 1008, 1056, 1080, 1092, 1104, 1176, 1240, 1260, 1344, 1368 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..53.

PROG

(PARI) for(n=1, 2000, if(0<sum(i=1, n, if(lcm(sigma(i), eulerphi(i))-n, 0, 1)), print1(n, ", ")))

CROSSREFS

Sequence in context: A324653 A094025 A336612 * A124637 A047173 A116653

Adjacent sequences:  A070284 A070285 A070286 * A070288 A070289 A070290

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, May 10 2002

STATUS

approved

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Last modified December 3 04:20 EST 2021. Contains 349445 sequences. (Running on oeis4.)