A243804 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.

36, 84, 382, 593, 1526, 2070, 4023, 9536, 11535, 22050, 31552, 36034, 49032, 76464, 113887, 125138, 176940, 216419, 233932, 313011, 371787, 480984, 666608, 767403, 811022, 925567, 974900, 1104796, 1749737, 1948447, 2298322, 2393928, 3129862, 3248932, 3750166, 4305141, 4682343, 5332158

Offset

3,1

Comments

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

Links

Table of n, a(n) for n=3..40.

Crossrefs

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

Sequence in context: A254648 A202330 A226264 * A043183 A039360 A043963

Adjacent sequences: A243801 A243802 A243803 * A243805 A243806 A243807

Keyword

nonn

Author

Vladimir Shevelev and Peter J. C. Moses, Jun 10 2014

Status

approved