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A133660
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No sum of 2 or more terms equals a prime.
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5
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OFFSET
| 1,2
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COMMENTS
| Sequence is infinite since the primes have density 0. [Charles R Greathouse IV, Apr 28, 2011]
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EXAMPLE
| 5 is a term of the series, as 5+1, 5+3 and 5+3+1 are all not prime. The next term, 87, is the next number n such that n+1, n+3, n+1+3, n+5, n+1+5, n+3+5 and n+1+3+5 are all not prime.
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MATHEMATICA
| (* first do *) Needs["Combinatorica`"] (* then *) lst = {}; g[k_] := Block[{j = 1, l = 2^Length@lst}, While[j < l && !PrimeQ[Plus @@ NthSubset[j, lst] + k], j++ ]; If[j == l, False, True]]; f[n_] := Block[{k = lst[[ -1]] + 1}, While[g[k] == True, k++ ]; AppendTo[lst, k]; k]; Do[Print@f@n, {n, 10}]. - Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 31 2007
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CROSSREFS
| Cf. A052349, A133661.
Sequence in context: A062214 A144617 A107655 * A057663 A056244 A173487
Adjacent sequences: A133657 A133658 A133659 * A133661 A133662 A133663
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KEYWORD
| more,nonn
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AUTHOR
| Randy L. Ekl (Randy.Ekl(AT)Motorola.com), Dec 28 2007
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EXTENSIONS
| a(9) from Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 31 2007
a(10) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Feb 15 2008
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