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Search: id:A104645
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| A104645 |
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Difference between the previous and the next primes to x, where x is the number obtained from concatenation of the first n primes(A019158). |
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+0
1
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| 5, 10, 6, 20, 24, 24, 60, 18, 48, 100, 48, 156, 74, 88, 68, 42, 126, 366, 106, 186, 136, 228, 104, 30, 246, 52, 218, 814, 58, 536, 174, 90, 924, 180, 298, 120, 330, 96, 508, 504, 60, 762, 588, 330, 138, 552, 726, 452, 634, 660, 354, 534, 1770, 52, 262, 834, 790, 250
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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a(n)=A007918(A019158(n))-A007917(A019158(n))
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EXAMPLE
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n=4, Concatenate {2,3,5,7} gives 2357. It is between the closest primes 2371 and 2351 and their difference is a(4)=20.
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MATHEMATICA
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<<NumberTheory`NumberTheoryFunctions` sz[x_] :=FromDigits[Flatten[Table[IntegerDigits[Prime[j]], {j, 1, x}], 1]] Table[NextPrime[sz[w]]-PreviousPrime[sz[w]], {w, 1, 100}]
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CROSSREFS
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Cf. A019158, A074809, A104462, A104463, A007918, A007917.
Sequence in context: A046795 A005093 A103697 this_sequence A067843 A109360 A141622
Adjacent sequences: A104642 A104643 A104644 this_sequence A104646 A104647 A104648
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Mar 18 2005
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