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A073258 Numbers n such that GCD[c(n),n]=GCD[A002808(n),n]=A064814(n)=1 where c(n) = n-th composite number. +0
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1, 3, 4, 8, 9, 11, 13, 17, 19, 23, 25, 27, 29, 31, 33, 35, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 49, 53, 57, 58, 59, 61, 66, 67, 68, 69, 71, 73, 79, 83, 84, 85, 86, 87, 88, 89, 90, 91, 92, 94, 95, 97, 100, 101, 103, 106, 107, 108, 109, 111, 113, 115, 116, 117, 118, 119 (list; graph; listen)
OFFSET

1,2

EXAMPLE

n=256: composite[256]=323=17.19, GCD[323,256]=1, 256 is here.

MATHEMATICA

c[x_] := FixedPoint[x+PrimePi[ # ]+1&, x]; t=Table[0, {256}]; s=0; k=0; Do[s=GCD[c[n], n]; If[Equal[s, 1], k=k+1; t[[k]]=n; Print[{k, n}]], {n, 1, 256}] t

CROSSREFS

Cf. A064814, A002808, A073255-A073264.

Sequence in context: A006520 A054204 A050003 this_sequence A002156 A058593 A047204

Adjacent sequences: A073255 A073256 A073257 this_sequence A073259 A073260 A073261

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Jul 22 2002

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Last modified December 15 00:47 EST 2009. Contains 170825 sequences.


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