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A007996 Primes that divide at least one term of the sequence f given by f(1) = 2, f(n+1) = n^2-n+1. +0
4
2, 3, 7, 13, 43, 73, 139, 181, 547, 607, 1033, 1171, 1459, 1861, 1987, 2029, 2287, 2437, 4219, 4519, 6469, 7603, 8221, 9829, 12763, 13147, 13291, 13999, 15373, 17881, 17977, 19597, 20161, 20479, 20641, 20857, 20929, 21661, 23689, 23773, 27031 (list; graph; listen)
OFFSET

1,1

COMMENT

Or, let S_1 = [2] and let S_{n+1} = list formed by sorting the union of S_n together with all prime factors of 1 + Product_i S_n(i) into increasing order; sequence is limit as n -> infinity of S_n.

Prime divisors of the terms of Sylverster's sequence A000058. - Max Alekseyev (maxale(AT)gmail.com), Jan 03 2004. Also of A007018. - N. J. A. Sloane (njas(AT)research.att.com), Jan 27 2007

REFERENCES

R. W. K. Odoni, On the prime divisors of the sequence w_{n+1} = 1+w_1 ... w_n, J. London Math. Soc. 32 (1985), 1-11.

Filip Saidak, A New Proof of Euclid's Theorem, Amer. Math. Monthly, Dec 2006

LINKS

Eric Weisstein's World of Mathematics, Sylvester's sequence

MAPLE

n := 1; for p do if isprime(p) then x := 2 mod p; S := {}; while not member(x, S) do if x=0 then a[n] := p; n := n+1; break; fi; S := S union {x}; x := (x^2-x+1) mod p; od; fi; od;

CROSSREFS

The missing primes form A096264.

Cf. A000058, A014546, A091335, A091336.

Sequence in context: A078749 A046062 A096263 this_sequence A085872 A075059 A070858

Adjacent sequences: A007993 A007994 A007995 this_sequence A007997 A007998 A007999

KEYWORD

nonn

AUTHOR

Bennett Battaile (bennett.battaile(AT)autodesk.com)

EXTENSIONS

More terms from Max Alekseyev (maxale(AT)gmail.com), Jan 03 2004

Entry revised by N. J. A. Sloane (njas(AT)research.att.com), Jan 28 2007

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Last modified November 25 20:09 EST 2009. Contains 167514 sequences.


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