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A051999 Minimal value w such that A051953(w) = w - Phi(w) is prime and w has n prime divisors. 0
4, 15, 255, 5865, 170085, 5437705, 226473065, 10380578845, 494390700895, 43592479037107 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

a(11) <= 2995513256722805. - Donovan Johnson, Feb 06 2010

LINKS

Table of n, a(n) for n=1..10.

EXAMPLE

a(1)=2^2, a(2)=3*5, a(3)=3*5*17, a(4)=3*5*17*23, a(5)=3*5*17*23*29, a(6)=5437705=5*7*13*17*19*37 with 1,2,3,4,5,6 prime divisors, respectively. The generated primes of form w - Phi(w) are as follows: 2, 7, 127, 3049, 91237, 2452721.

CROSSREFS

Cf. A051953, A050530.

Sequence in context: A153060 A139244 A090115 * A048731 A000881 A109923

Adjacent sequences:  A051996 A051997 A051998 * A052000 A052001 A052002

KEYWORD

nonn

AUTHOR

Labos Elemer, Jan 05 2000

EXTENSIONS

a(7)-a(10) from Donovan Johnson, Feb 06 2010

STATUS

approved

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Last modified April 24 04:23 EDT 2019. Contains 322406 sequences. (Running on oeis4.)