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Search: id:A155547
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| A155547 |
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a(n) = prime(n) without prime digits in n. |
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+0
1
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| 2, 7, 13, 19, 23, 29, 31, 43, 53, 61, 67, 173, 179, 193, 199, 223, 227, 281, 283, 311, 317, 337, 347, 409, 419, 433, 443, 457, 461, 463, 467, 491, 503, 521, 523, 541, 547, 569, 577, 593, 599, 601, 607, 619, 641, 647, 653, 809, 811, 827, 839, 857, 859, 941, 947
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Prime digit = 2, 3, 5 or 7.
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FORMULA
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a(n)=A000040(A084984(n)). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 25 2009]
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MAPLE
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isA084984 := proc(n) local dgs ; dgs := convert(convert(n, base, 10), set) ; if dgs intersect {2, 3, 5, 7} <> {} then false; else true; fi; end: A084984 := proc(n) option remember ; local a ; if n = 1 then 1; else for a from procname(n-1)+1 do if isA084984(a) then RETURN(a) ; fi; od; fi; end: A155547 := proc(n) ithprime(A084984(n)) ; end: for n from 1 to 80 do printf("%d, ", A155547(n)) ; od: [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 25 2009]
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CROSSREFS
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Cf. A000027, A000040.
Sequence in context: A106911 A019370 A001966 this_sequence A007821 A156007 A067774
Adjacent sequences: A155544 A155545 A155546 this_sequence A155548 A155549 A155550
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KEYWORD
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nonn,base
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AUTHOR
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Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 24 2009
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