A166466 Trisection a(n) = A000265(3n).

3, 3, 9, 3, 15, 9, 21, 3, 27, 15, 33, 9, 39, 21, 45, 3, 51, 27, 57, 15, 63, 33, 69, 9, 75, 39, 81, 21, 87, 45, 93, 3, 99, 51, 105, 27, 111, 57, 117, 15, 123, 63, 129, 33, 135, 69, 141, 9, 147, 75, 153, 39, 159, 81, 165, 21, 171, 87, 177, 45, 183, 93, 189, 3, 195, 99, 201, 51

Offset

1,1

Comments

The other trisections are A067745 and A075677.

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Formula

A000265(A007283(n)) = 3. a(A007283(n)) = 9.

a(n) = 3*A000265(n).

Sum_{k=1..n} a(k) ~ n^2. - Amiram Eldar, Aug 30 2024

Maple

A166468 := proc(n) A000265(3*n) ; end: seq(A166468(n), n=1..80) ; # R. J. Mathar, Oct 21 2009

Mathematica

A166466[n_]:= If[n==0, 0, 3*n/2^IntegerExponent[n, 2]];
Table[A166466[n], {n, 100}] (* based on Michael Somos's code of A000265 *) (* G. C. Greubel, Jul 31 2024 *)

Prog

(Magma)
A166466:= func< n | 3*n/2^Valuation(n, 2) >;
[A166466(n): n in [1..120]]; // G. C. Greubel, Jul 31 2024
(SageMath)
def A166466(n): return 3*n//2^valuation(n, 2)
[A166466(n) for n in (1..121)] # G. C. Greubel, Jul 31 2024
(PARI) a(n)=3*n>>valuation(n, 2);
vector(100, n, a(n))  \\ Joerg Arndt, Aug 01 2024

Crossrefs

Cf. A000265, A007283, A067745, A075677.

Sequence in context: A036553 A339318 A359600 * A068219 A337461 A157031

Adjacent sequences: A166463 A166464 A166465 * A166467 A166468 A166469

Keyword

nonn,easy

Author

Paul Curtz, Oct 14 2009

Extensions

Comments turned into formulas by R. J. Mathar, Oct 21 2009

Status

approved