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A053647
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First term of first sequence of n primes in arithmetic progression with a common difference equal to the product of first n primes.
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0
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2, 5, 7, 13, 37, 73, 7937, 7703, 272809, 640943, 5378959, 116137159, 3708797237, 114649314209, 158317270283
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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For n=3, product of first 3 primes is 30. The first arithmetic progression of 3 primes with difference 30 starts at 7 (7, 37, 67), so a(3)=7.
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MATHEMATICA
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(* This program is not convenient beyond 10 terms *) r[p1_, n_] := Reduce[p[1] = p1; Equal @@ Append[Table[p[k + 1] - p[k], {k, 1, n - 1}], Product[Prime[k], {k, 1, n}]], p[2], Primes]; a[n_] := a[n] = Catch[For[k = 1, k <= 10^5, k++, If[r[p1 = Prime[k], n] =!= False, Throw[p1]]]]; Table[Print[a[n]]; a[n], {n, 1, 10}] (* Jean-François Alcover, Dec 27 2012 *)
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CROSSREFS
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KEYWORD
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hard,nonn,nice
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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