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A101593
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a(n) = number of m <= 2^n which are in A075190, i.e. such that A056929(m)=0.
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1
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1, 2, 3, 6, 9, 14, 19, 34, 62, 109, 202, 336, 587, 1100, 2003, 3630, 6784, 12607, 23647, 44206, 83510, 157851
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| A056929(m)=0 iff m^2 = (A007491(m)+A053001(m))/2 = average of the next higher and next lower primes.
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PROG
| (PARI) a(n)=sum(i=2, 2^n, !A056929(i))
(PARI) a(n)=sum(i=2, 2^n, nextprime(i^2)+precprime(i^2)==2*i^2)
(PARI) t=0; vector(15, n, t=sum(i=1/2<<n+1, 1<<n, nextprime(i^2)+precprime(i^2)==2*i^2, t))
(PARI) for(n=16, 30, print1(t=sum(i=2^(n-1)+1, 2^n, nextprime(i^2)+precprime(i^2)==2*i^2, t), ", "))
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CROSSREFS
| Cf. A056929, A007491, A053001, A075190, A069495.
Sequence in context: A074150 A061925 A073736 * A084628 A002096 A094055
Adjacent sequences: A101590 A101591 A101592 * A101594 A101595 A101596
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KEYWORD
| nonn
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AUTHOR
| Zak Seidov (zakseidov(AT)yahoo.com) and M. F. Hasler (Maximilian.Hasler(AT)gmail.com), Dec 27 2007
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