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A154568
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Composites of the form sum of digits of n + sum of digits of prime(n).
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0
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8, 10, 15, 18, 14, 12, 6, 9, 12, 15, 22, 16, 10, 20, 16, 10, 18, 21, 8, 14, 10, 20, 22, 16, 21, 26, 15, 22, 16, 18, 21, 26, 15, 24, 18, 14, 21, 15, 24, 22, 30, 20, 22, 15, 18, 20, 27, 26, 26, 24, 27, 34, 34, 21, 21, 22, 25, 32, 32, 28, 22, 27, 27, 36, 30, 25, 28, 18, 20, 18, 25
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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EXAMPLE
| If n=3 and prime=5, then 3+5=8(c0mposite)=a(1). If n=6 and prime=13, then 6+1+3=10(composite)=a(2), etc.
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MAPLE
| Contribution from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 05 2010: (Start)
A007953 := proc(n) add(d, d=convert(n, base, 10)) ; end proc:
for n from 1 to 300 do a := A007953(n) +A007953(ithprime(n)) ; if a> 4 and not isprime(a) then printf("%d, ", a ) ; end if; end do: (End)
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CROSSREFS
| Cf. A000040, A002808.
Sequence in context: A100718 A063190 A101763 * A020940 A058633 A165143
Adjacent sequences: A154565 A154566 A154567 * A154569 A154570 A154571
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KEYWORD
| nonn,base
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AUTHOR
| Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Jan 12 2009
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EXTENSIONS
| Corrected (a(36) changed, a(48) inserted etc.) by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), May 05 2010
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