A058011 Consider the sequence {b(m)} of nonprimes; sequence gives values of m where gcd{m, b(m)} increases.

1, 4, 6, 8, 27, 30, 33, 96, 100, 120, 330, 335, 340, 350, 355, 360, 1008, 1080, 1092, 1116, 1122, 1128, 1134, 3059, 3066, 3073, 3080, 3087, 3094, 8408, 8424, 8440, 8456, 8464, 8472, 23526, 23535, 24300, 64540, 64580, 64610, 64620, 64650, 64690, 64700

Offset: 0

Author

Robert G. Wilson v, Nov 13 2000

Keywords

• nonn

Examples

			a(4) = 8 because eight is the fourth nonprime number and GCD(4,8) > GCD(3,6).
		

Crossrefs

Cf. A058012. Apart from initial term same as A057809.

Programs

Mathematica

r=0; Do[a = GCD[n, n - PrimePi[n] ]; If[a > r, r = a; Print[n]], {n, 1, 10^5} ]