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Search: id:A115210
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| A115210 |
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a(0)=0. a(n) = number of earlier terms of the sequence which when added to n produce a composite number. |
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+0
4
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| 0, 0, 0, 0, 4, 1, 5, 2, 7, 7, 7, 6, 7, 7, 13, 13, 8, 11, 13, 14, 19, 19, 14, 15, 13, 23, 23, 23, 20, 21, 16, 25, 28, 27, 21, 32, 24, 29, 30, 31, 24, 32, 34, 33, 38, 37, 29, 35, 34, 43, 41, 43, 38, 43, 35, 47, 46, 49, 44, 44, 35, 54, 52, 52, 49, 52, 42, 55, 56, 55, 56, 57, 54, 59
(list; graph; listen)
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OFFSET
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0,5
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EXAMPLE
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Adding 6 to the first 6 terms (terms 0 through 5) of the sequence gives [6,6,6,6,10,7]. Of these terms, five are composite, so a(6) = 5.
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PROGRAM
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(PARI) seq=vector(200); print1(0, ", "); for(j=1, 190, count=0; for(k=0, j-1, if(isprime(j+seq[k+1])==0 && (j+seq[k+1])>1, count=count+1; )); seq[j+1]=count; print1(seq[j+1], ", ")) - Matthew Conroy Feb 07 2006
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CROSSREFS
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Cf. A115207, A115208, A115209.
Adjacent sequences: A115207 A115208 A115209 this_sequence A115211 A115212 A115213
Sequence in context: A035590 A080414 A067061 this_sequence A030352 A104571 A105721
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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), Jan 16 2006
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EXTENSIONS
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More terms from Matthew Conroy Feb 07 2006
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