A050673 a(n) is the smallest prime such that the number of primes produced according to rules stipulated in Honaker's A048853 is n.

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

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

Table of n, a(n) for n=1..28.

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