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Number of numbers k in interval [(p_n)^2+1, (p_n)^4] for which lpf(k-1)>lpf(k-3)>=p_n, such that {k-3, k-1} is not a pair of twin primes, where p_n=prime(n) and lpf = A020639.
4

%I #21 Oct 21 2014 00:03:38

%S 36,84,382,593,1526,2070,4023,9536,11535,22050,31552,36034,49032,

%T 76464,113887,125138,176940,216419,233932,313011,371787,480984,666608,

%U 767403,811022,925567,974900,1104796,1749737,1948447,2298322,2393928,3129862,3248932,3750166,4305141,4682343,5332158

%N Number of numbers k in interval [(p_n)^2+1, (p_n)^4] for which lpf(k-1)>lpf(k-3)>=p_n, such that {k-3, k-1} is not a pair of twin primes, where p_n=prime(n) and lpf = A020639.

%C a(n) and A243803(n) approximate each other with the relative error tending to zero with growth of n.

%Y Cf. A020639, A242719, A242720, A242847, A242758, A243803.

%K nonn

%O 3,1

%A _Vladimir Shevelev_ and _Peter J. C. Moses_, Jun 10 2014