A072610 Values of transition of A072608(n) from alternating behavior (0,1,0,1,..) into steadily-1 (1,1,1,..) behavior or changing back. Expressing in terms of A072609(n): at n values it switches from steadily 0 into steadily 1 successive values or back.

3, 11, 29, 67, 69, 71, 179, 181, 189, 441, 1059, 2699, 6453, 6459, 6471, 15927, 40071, 40083, 40121, 100363, 251705, 251707, 251709, 251721, 251723, 251735, 251737, 251741, 251761, 637233, 637235, 637319, 637321, 637323, 637325, 637329, 637333

Offset: 1

Author

Labos Elemer, Jun 24 2002

Keywords

• nonn

Comments

Values of n such that A072609(n) != A072609(n+1).

Switching zones appear in clusters of n. Remainder A004648 either drops or starts to increase at these values of n.

Examples

			At n=637330...637370 the change of remainder A004648 is as follows: {..637323, 4, 13, 4, 637333, 637327, 637335, 637323, 637319, 637325, 637321, 4, 11, 4, 7, 34, 29, 26, 17, 44, 43, 46, 41, 38, 49, 52, 49, 44, 37, 28, 37..}
		

Crossrefs

Cf. A004648, A072608, A072609.

Programs

Mathematica

mm[x_] := Mod[Mod[Prime[x], x], 2];
pm[x_] := mm[x]*mm[x+1];
Do[s1=pm[n]; s2=pm[n+1]; If[ !Equal[s1, s2], Print[n]], {n, 10^9}]