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A050440 Sixth-order composites. 2
56, 69, 77, 78, 84, 94, 100, 105, 106, 115, 124, 125, 126, 133, 140, 141, 145, 152, 156, 162, 164, 165, 170, 174, 183, 184, 188, 198, 202, 203, 206, 209, 212, 213, 218, 222, 231, 235, 236, 242, 243, 253, 256, 258, 259, 262, 264, 266, 270, 272, 278, 284 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

LINKS

N. Fernandez, An order of primeness, F(p)

FORMULA

Let C(n) be the n-th composite number, with C(1)=4. Then these are numbers C(C(C(C(C(C(n)))))).

EXAMPLE

C(C(C(C(C(C(1)))))) = C(C(C(C(C(4))))) = C(C(C(C(9)))) = C(C(C(16))) = C(C(26)) = C(39) = 56. So 56 is in the sequence. So 77 is in the sequence.

MAPLE

C := remove(isprime, [$4..1000]): seq(C[C[C[C[C[C[n]]]]]], n=1..100);

CROSSREFS

A049076-A049081, A006450, A050435, A050436, A050438, A050439.

Sequence in context: A039428 A043251 A044031 * A043158 A039335 A043938

Adjacent sequences:  A050437 A050438 A050439 * A050441 A050442 A050443

KEYWORD

easy,nonn

AUTHOR

Michael Lugo (mlugo(AT)thelabelguy.com), Dec 22 1999

EXTENSIONS

More terms from Asher Auel (asher.auel(AT)reed.edu) Dec 15 2000

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Last modified February 17 23:29 EST 2012. Contains 206085 sequences.