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Search: id:A064961
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| A064961 |
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Composite-then-prime recurrence; a(2n) = a(2n-1)-th composite and a(2n+1) = a(2n)-th prime and a(1) = 1. |
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+0 2
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| 1, 4, 7, 14, 43, 62, 293, 366, 2473, 2892, 26317, 29522, 344249, 376259, 5429539, 5831545, 101291779, 107457490, 2198218819, 2310909505, 54720307351, 57128530327, 1543908890351, 1602887567085, 48931564656397, 50589163077046
(list; graph; listen)
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OFFSET
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1,2
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LINKS
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N. Fernandez, An order of primeness, F(p)
Andrew R. Booker, The Nth Prime Page
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MATHEMATICA
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Composite[n_Integer] := FixedPoint[n + PrimePi[ # ] + 1 &, n + PrimePi[n] + 1]; a = {1, 4}; b = 4; Do[ If[ !PrimeQ[b], b = Prime[b], b = Composite[b]]; a = Append[a, b], {n, 1, 23}]; a
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CROSSREFS
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Cf. A007097, A006508 & A064960, see also A057450, A057451, A057452, A057453, A057456 & A057457 and A049076, A049077, A049078, A049079, A049080 & A049081.
Sequence in context: A132753 A049945 A076586 this_sequence A137053 A049832 A092309
Adjacent sequences: A064958 A064959 A064960 this_sequence A064962 A064963 A064964
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KEYWORD
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nonn
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AUTHOR
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Robert G. Wilson v (rgwv(AT)rgwv.com), Oct 29 2001
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