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Search: id:A134694
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| A134694 |
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a(0) = 2; a(n) = least prime p such that p >= a(n-1) + 2^n |
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+0
1
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| 2, 5, 11, 19, 37, 71, 137, 269, 541, 1061, 2087, 4139, 8237, 16433, 32831, 65599, 131143, 262217, 524369, 1048661, 2097257, 4194409, 8388733, 16777381, 33554639, 67109071, 134217943, 268435697, 536871157, 1073742073, 2147483929
(list; graph; listen)
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OFFSET
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0,1
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COMMENT
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Primes separated by at least successive powers of 2.
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EXAMPLE
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a(0) = 2 (by definition)
a(1) = 5 because 5 is the least prime >= 4 = 2 + 2^1
a(2) = 11 because 11 is the least prime >= 9 = 5 + 2^2
a(3) = 19 because 19 is the least prime >= 19 = 11 + 2^3
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MATHEMATICA
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a = {2}; Do[i = a[[ -1]]+2^n; While[ !PrimeQ[i], i++ ]; AppendTo[a, i], {n, 1, 50}]; a - Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jan 28 2008
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CROSSREFS
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Cf. A000040.
Sequence in context: A084572 A040105 A156768 this_sequence A121606 A166164 A097008
Adjacent sequences: A134691 A134692 A134693 this_sequence A134695 A134696 A134697
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KEYWORD
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easy,nonn
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AUTHOR
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Walter G. Carlini (wgcarlini(AT)charter.net), Jan 27 2008
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EXTENSIONS
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More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Jan 28 2008
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