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A067836 Let a(1)=2, f(n)=a(1)*a(2)*...*a(n-1) for n>=1, and a(n)=nextprime(f(n)+1)-f(n) for n>=2, where nextprime(x) is the smallest prime > x. +0
5
2, 3, 5, 7, 13, 11, 17, 19, 23, 37, 73, 29, 31, 43, 79, 53, 83, 67, 41, 47, 179, 149, 181, 103, 71, 59, 197, 167, 109, 137, 107, 251, 101, 157, 199, 283, 211, 277, 173, 127, 269, 61, 89, 271, 151, 191, 227, 311, 409, 577, 331, 281, 313, 307, 223, 491, 439, 233, 367 (list; graph; listen)
OFFSET

1,1

COMMENT

The terms are easily seen to be distinct. It is conjectured that every element is prime. Do all primes occur in the sequence?

LINKS

Frank Buss, Prime Puzzles - Frank Buss's Conjecture

Frank Buss, The B(n) function

MATHEMATICA

<<NumberTheory`PrimeQ` (* Load ProvablePrimeQ function, needed below. *)

f[1]=1; f[n_] := f[n]=f[n-1]a[n-1]; a[n_] := a[n]=Module[{i}, For[i=2, True, i++, If[ProvablePrimeQ[f[n]+i], Return[i]]]]

PROGRAM

(MuPAD) f := 1:for n from 1 to 50 do a := nextprime(f+2)-f:f := f*a:print(a) end_for

CROSSREFS

Cf. A062894 has the indices of the primes in this sequence. A071290 has the sequence of f's. Also see A067362, A068192.

Adjacent sequences: A067833 A067834 A067835 this_sequence A067837 A067838 A067839

Sequence in context: A126056 A126055 A126054 this_sequence A108546 A065107 A090420

KEYWORD

nonn

AUTHOR

Frank Buss (fb(AT)frank-buss.de), Feb 09 2002

EXTENSIONS

Edited by Dean Hickerson (dean(AT)math.ucdavis.edu), Mar 02 2002 and by Dean Hickerson and David W. Wilson (davidwwilson(AT)comcast.net) Jun 10 2002

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Last modified May 16 23:01 EDT 2008. Contains 139884 sequences.


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