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Search: id:A061448
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| A061448 |
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a(1) = 2; a(n+1) = smallest prime > a(n) with leading digit equal to final digit of a(n). |
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+0
2
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| 2, 23, 31, 101, 103, 307, 701, 1009, 9001, 10007, 70001, 100003, 300007, 700001, 1000003, 3000017, 7000003, 30000001, 100000007, 700000001, 1000000007, 7000000001, 10000000019, 90000000019, 90000000023, 300000000077
(list; graph; listen)
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OFFSET
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1,1
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LINKS
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Index entries for sequences related to final digits of numbers
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FORMULA
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a(n)=A054262(n-1), n>2. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 30 2009]
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EXAMPLE
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a(5) = 103, hence a(6) = 307.
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MATHEMATICA
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a[1]=2; a[n_] := (v=IntegerDigits[a[n-1]]; v1=If[v[[ -1]]>v[[1]], v[[ -1]]*10^(Length[v]-1), If[v[[ -1]]<v[[1]]||Length[v]==1, v[[ -1]]*10^Length[v], a[n-1]]]; For[m=v1+1, !PrimeQ[m], m++ ]; m); Table[a[n], {n, 35}]
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CROSSREFS
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Sequence in context: A049568 A049556 A049580 this_sequence A115233 A007510 A117242
Adjacent sequences: A061445 A061446 A061447 this_sequence A061449 A061450 A061451
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KEYWORD
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nonn,base
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), May 03 2001
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EXTENSIONS
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More terms from Larry Reeves (larryr(AT)acm.org), May 17 2001
Terms from a(18) added by Patrick De Geest (pdg(AT)worldofnumbers.com), Jun 04 2001.
Mathematica program from Farideh Firoozbakht (f.firoozbakht(AT)sci.ui.ac.ir), Aug 30 2003
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