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 A108583 Let b(n) = b(n-1)+A005185(n) [with what initial term?]; sequence gives primes of the form 1 + Product_{i=1..k} b(i). 0
 3, 13, 2593, 2426113 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,1 COMMENTS Using a sequence starting at 2 with a chaotic gap to simulate the primes, this is a Euclid prime analog. LINKS FORMULA b(n) = b(n-1)+A005185[[n]] a(m)=if Product[b[n], {n, 1, m}]+1 is prime then Product[b[n], {n, 1, m}]+1 MATHEMATICA Hofstadter[0] = Hofstadter[1] = 1 Hofstadter[n_Integer?Positive] := Hofstadter[n] = Hofstadter[n - Hofstadter[n - 1]] + Hofstadter[n - Hofstadter[n - 2]] a[1] = 2; a[n_] := a[n] = a[n - 1] + 2*Hofstadter[n] b = Flatten[Table[If[PrimeQ[Product[a[n], {n, 1, m}] + 1] == True, Product[a[n], {n, 1, m}] + 1, {}], {m, 1, 200}]] CROSSREFS Cf. A018239, A005185. Sequence in context: A177362 A138487 A022507 * A127855 A087333 A320041 Adjacent sequences:  A108580 A108581 A108582 * A108584 A108585 A108586 KEYWORD nonn AUTHOR Roger L. Bagula, Jul 05 2005 STATUS approved

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Last modified November 27 15:11 EST 2020. Contains 338683 sequences. (Running on oeis4.)