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

1,2

Comments

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

Links

Table of n, a(n) for n=1..44.

Example

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.

Sequence in context: A182235 A180304 A332824 * A056675 A062857 A061799

Adjacent sequences: A053143 A053144 A053145 * A053147 A053148 A053149

Keyword

more,nonn

Author

Labos Elemer, Feb 28 2000

Extensions

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

Status

approved