A053146 When cototient function (A051953) is iterated with initial value A002110(n), a(n) = number of iterates that are not powers of 2.

1, 2, 4, 6, 12, 11, 25, 22, 32, 26, 54, 55, 67, 68, 85, 117, 126, 113, 150, 166, 130, 178, 186, 207, 201, 194, 253, 255, 256, 295, 284, 309, 320, 315, 348, 347, 365, 398, 423, 425, 433, 459, 468, 488

Offset: 1

Author

Labos Elemer, Feb 28 2000

Keywords

• more
• nonn

Comments

In these iteration chains, the numbers that are not powers of 2 seem to be in the majority.

Examples

			n=6, A002110(6)=30030; the corresponding iteration chain is: {30030, 24270, 17806, 9238, 4798, 2400, 1760, 1120, 736, 384, 256, 128, 64, 32, 16, 8, 4, 2, 1, 0}. It has 20 terms, among which entries from the first to 10th, also the last 0, are not powers of 2, so a(6)=11.
		

Crossrefs

Cf. A002110, A051953.

Extensions

a(13)-a(44) from Donovan Johnson, May 13 2010