A351875 Positive difference of the distinct prime factors of A129521(n).

1, 2, 6, 18, 30, 36, 78, 96, 138, 156, 198, 210, 228, 270, 306, 330, 336, 366, 378, 438, 498, 546, 576, 600, 606, 618, 660, 690, 726, 810, 828, 876, 936, 966, 996, 1008, 1068, 1170, 1236, 1278, 1296, 1398, 1428, 1458, 1530, 1608, 1626, 1656, 1758, 1866, 2010, 2028, 2088, 2130

Offset: 1

Author

Wesley Ivan Hurt, Feb 22 2022

Keywords

• nonn

Examples

			a(4) = 18; A005383(4) - A005382(4) = 37 - 19 = 18.
		

Crossrefs

Cf. A005382, A005383, A129521.

Programs

Mathematica

Select[Prime[Range[350]], PrimeQ[2*# - 1] &] - 1 (* Amiram Eldar, Feb 23 2022 *)

Formula

a(n) = A005383(n) - A005382(n).

a(n) = A005382(n) - 1. - Amiram Eldar, Feb 23 2022