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A147850
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Parity of the digits sum of sum_{j=8*n-7..8*n} prime(j).
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1
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1, 0, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 0
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Odd parities of the sum in the n-th block of 8 consecutive primes are represented by a(n)=1, even parities by a(n)=0.
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FORMULA
| a(n) = 1-A147781(n).
a(n) = A007953(17982*A127335(8*n-7)) mod 2. [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 06 2009]
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EXAMPLE
| 2+3+5+7+11+13+17+19 = 1384614 (1+3+8+4+6+1+4) = 27 (1).
23+29+31+37+41+43+47+53 = 5466528 (5+4+6+6+5+2+8) = 36 (0)
461+463+467+479+487+491+499+503 = 69230700 (6+9+2+3+7) = 27 (1).
509+521+523+541+547+557+563+569= 77862060 (7+7+8+6+2+6) = 36 (0)
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MAPLE
| A127335 := proc(n) add(ithprime(i), i=n..n+7) ; end:
A007953 := proc(n) add(i, i=convert(n, base, 10)) ; end:
A147850 := proc(n) A007953(17982*A127335(8*n-7)) mod 2 ; end:
for n from 1 to 200 do printf("%a, ", A147850(n)) ; od: [From R. J. Mathar, Jan 06 2009]
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CROSSREFS
| Cf. A147781.
Sequence in context: A040053 A004569 A100060 * A099991 A091069 A087003
Adjacent sequences: A147847 A147848 A147849 * A147851 A147852 A147853
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KEYWORD
| easy,nonn,base
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AUTHOR
| E. J. Vening (permutate(AT)gmail.com), Nov 15 2008
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EXTENSIONS
| More terms from R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jan 06 2009
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