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Search: id:A109277
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| A109277 |
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Slowest increasing sequence: a(n) is a prime closest to the sum of all previous terms. |
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+0
2
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| 2, 2, 3, 7, 13, 29, 53, 109, 223, 439, 881, 1759, 3517, 7039, 14071, 28151, 56299, 112601, 225217, 450413, 900821, 1801669, 3603317, 7206631, 14413253, 28826519, 57653027, 115306073, 230612149, 461224289, 922448587, 1844897167, 3689794321
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Cf. A109277 fastest increasing sequence.
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EXAMPLE
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a(1)=2, sum(1)=2; prime closest to sum is 2, hence a(2)=2, sum(2)=4; there are two primes 3 and 5 closest to sum(2), we choose the smallest one, hence a(3)=3, sum(3)=7, etc.
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MATHEMATICA
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s={2}; su=2; Do[If[PrimeQ[su], a=su, pp=PrimePi[su]; prv=Prime[pp]; nxt=Prime[pp+1]; a=If[su-prv>nxt-su, nxt, prv]]; AppendTo[s, a]; Print[a]; su+=a, {i, 42}]; s
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CROSSREFS
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Cf. A109278.
Sequence in context: A049905 A167348 A068524 this_sequence A093437 A060357 A064714
Adjacent sequences: A109274 A109275 A109276 this_sequence A109278 A109279 A109280
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Jun 25 2005
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