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 A192530 Index-list (modified) of the primes generated at A192583. 3
 1, 2, 3, 3, 4, 5, 6, 7, 9, 11, 12, 13, 15, 16, 19, 22, 23, 24, 27, 28, 33, 34, 35, 39, 41, 48, 57, 61, 66, 72, 95, 102, 114, 117, 128, 143, 148, 184, 196, 227, 228, 266, 302, 325, 367, 417, 471, 606, 882, 916, 1071, 1539, 4305 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Besides the generated primes 2,5,11,13,17,..., the initial numbers 4,6,8 in A192583 are represented here by index of nearest lower prime. LINKS EXAMPLE A192583=(2,4,5,6,8,11,13,17,23,...).  a(1)=1 because the index of 2 is 1; a(2)=2 because, for term #2 of A192530, which is 4, the nearest prime <4 is 3, which has index 2; a(3)=3 because the index of 5 is 3.  ("Nearest prime down" for nonprimes is given by PrimePi in the Mathematica program.) MATHEMATICA start = {2, 4, 6, 8}; primes = Table[Prime[n], {n, 1, 10000}]; f[x_, y_] := If[MemberQ[primes, x*y + 1], x*y + 1] b[x_] :=   Block[{w = x},    Select[Union[      Flatten[AppendTo[w,        Table[f[w[[i]], w[[j]]], {i, 1, Length[w]}, {j, 1, i}]]]], # <       10000000 &]]; t = FixedPoint[b, start]  (* A192583 *) PrimePi[t] (* A192530 Nonprimes 4, 6, 8 are represented by "next prime down". *) CROSSREFS Cf. A192583. Sequence in context: A039732 A011876 A029036 * A281744 A026838 A182229 Adjacent sequences:  A192527 A192528 A192529 * A192531 A192532 A192533 KEYWORD nonn,fini,full AUTHOR Clark Kimberling, Jul 04 2011 STATUS approved

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Last modified August 7 16:00 EDT 2022. Contains 355994 sequences. (Running on oeis4.)