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 A050673 a(n) is the smallest prime such that the number of primes produced according to rules stipulated in Honaker's A048853 is n. 13
 6983, 4409, 2, 97, 29, 23, 11, 13, 131, 101, 107, 1459, 1297, 1423, 15731, 13597, 105967, 249533, 1006391, 2391041, 10866913, 77538289, 107640251, 120988597, 119628479, 10168288073, 1812918883, 115829122963 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS a(26) > 10^10. a(27) = 1812918883. a(n) > 10^10 for n >= 28. - Donovan Johnson, May 08 2010 a(29) > 1.9*10^11. - Giovanni Resta, Aug 14 2013 LINKS FORMULA A048853(a(n))=n. a(n) is prime. a(n)>=A050662(n). - R. J. Mathar, Apr 25 2006 MAPLE A048853 := proc(n::integer) local resul, ddigs, d, c, tmp, tst ; resul := 0 ; ddigs := convert(n, base, 10) ; for d from 1 to nops(ddigs) do for c from 0 to 9 do if c = 0 and d = nops(ddigs) then continue ; else if c <> op(d, ddigs) then tmp := [op(1..d-1, ddigs), c, op(d+1..nops(ddigs), ddigs)] ; tst := sum(op(i, tmp)*10^(i-1), i=1..nops(tmp)) ; if isprime(tst) then resul := resul+1 ; fi ; fi ; fi ; od : od ; RETURN(resul) ; end: A050673 := proc(n::integer) local i, p; for p from 1 to 10000000 do i := ithprime(p) ; if A048853(i) = n then RETURN(i) ; fi ; od ; RETURN(-1) ; end : for n from 1 to 90 do print(A050673(n)) ; od ; # R. J. Mathar, Apr 25 2006 CROSSREFS Cf. A048853, first terms of A050663-A050672, A050662. Sequence in context: A305718 A237237 A251651 * A050663 A114615 A209879 Adjacent sequences:  A050670 A050671 A050672 * A050674 A050675 A050676 KEYWORD nonn,base,more AUTHOR Patrick De Geest, Jul 15 1999 EXTENSIONS a(22)-a(25) from Donovan Johnson, May 08 2010 a(26) and a(28) from Giovanni Resta, Aug 14 2013 STATUS approved

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Last modified August 14 08:08 EDT 2020. Contains 336480 sequences. (Running on oeis4.)