A243803 Number of numbers k in interval [(p_n)^2+1, (p_n)^4] for which lpf(k-3)>lpf(k-1)>=p_n, where p_n=prime(n) and lpf = A020639.

40, 85, 393, 625, 1557, 2106, 4069, 9558, 11476, 22060, 31530, 35998, 49142, 76678, 113799, 125010, 176824, 216378, 234064, 313511, 372054, 481764, 668344, 768307, 811635, 926452, 975785, 1105924, 1751993, 1949976, 2299392, 2394921, 3130534, 3250605, 3751262, 4306910, 4683674, 5332960

Offset

3,1

Comments

a(n) and A243804(n) approximate each other with a small relative error.

Positions n for which a(n) < A243804(n) are 11, 13, 14, 17, 18, 19, 20 (...).

Links

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

Crossrefs

Cf. A020639 (lpf), A242719, A242720, A242847, A242758, A243804.

Sequence in context: A174052 A141528 A160282 * A203855 A188335 A185718

Adjacent sequences: A243800 A243801 A243802 * A243804 A243805 A243806

Keyword

nonn

Author

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

Status

approved