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Search: id:A131199
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| A131199 |
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a(0)=2. For n>=1, a(n) = a(n-1)+n if a(n-1) is composite; a(n) = a(n-1)*n if a(n-1) is prime. |
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1
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| 2, 2, 4, 7, 28, 33, 39, 46, 54, 63, 73, 803, 815, 828, 842, 857, 13712, 13729, 247122, 247141, 4942820, 4942841, 4942863, 4942886, 4942910, 4942935, 4942961, 4942988, 4943016, 4943045, 4943075, 4943106, 4943138, 4943171, 4943205, 4943240
(list; graph; listen)
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OFFSET
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0,1
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MAPLE
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a[0]:=2: for n to 30 do if isprime(a[n-1])=false then a[n]:=a[n-1]+n else a[n]:=a[n-1]*n end if end do: seq(a[n], n=0..30); - Emeric Deutsch (deutsch(AT)duke.poly.edu), Oct 24 2007
A131199 := proc(n) option remember ; if n = 0 then 2 ; else if isprime(A131199(n-1)) then n*A131199(n-1) ; else n+A131199(n-1) ; fi ; fi ; end: seq(A131199(n), n=0..80) ; - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 30 2007
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CROSSREFS
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Cf. A083524.
Sequence in context: A014266 A032441 A065844 this_sequence A112059 A093094 A045777
Adjacent sequences: A131196 A131197 A131198 this_sequence A131200 A131201 A131202
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Oct 21 2007
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EXTENSIONS
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More terms from Emeric Deutsch (deutsch(AT)duke.poly.edu) and R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Oct 24 2007
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