A324468 a(n) = r(n) + r(n+1) + r(n+2), where r(n) is the ruler sequence A007814.

1, 3, 2, 3, 1, 4, 3, 4, 1, 3, 2, 3, 1, 5, 4, 5, 1, 3, 2, 3, 1, 4, 3, 4, 1, 3, 2, 3, 1, 6, 5, 6, 1, 3, 2, 3, 1, 4, 3, 4, 1, 3, 2, 3, 1, 5, 4, 5, 1, 3, 2, 3, 1, 4, 3, 4, 1, 3, 2, 3, 1, 7, 6, 7, 1, 3, 2, 3, 1, 4, 3, 4, 1, 3, 2, 3, 1, 5, 4, 5, 1, 3, 2, 3, 1

Offset

1,2

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..10000

Formula

1 <= a(n) <= 1 + log_2(n+2). - Charles R Greathouse IV, Jul 01 2022

Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = 3. - Amiram Eldar, Sep 10 2024

Mathematica

Table[Sum[IntegerExponent[n + k, 2], {k, 0, 2}], {n, 100}] (* Vincenzo Librandi, Mar 10 2019 *)

Prog

(Magma) [&+[Valuation(n+k, 2): k in [0..2]]: n in [1..70]]; // Vincenzo Librandi, Mar 10 2019
(PARI) a(n) = sum(k=0, 2, valuation(n+k, 2)); \\ Michel Marcus, Mar 10 2019
(Python)
def A324468(n): return (~n & n-1).bit_length()+(~(n+1) & n).bit_length()+(~(n+2) & n+1).bit_length() # Chai Wah Wu, Jul 01 2022

Crossrefs

Cf. A001511, A007814, A050603 (r(n)+r(n+1)), A324465.

Sequence in context: A236027 A220128 A371172 * A131498 A236455 A033093

Adjacent sequences: A324465 A324466 A324467 * A324469 A324470 A324471

Keyword

nonn,easy

Author

N. J. A. Sloane, Mar 03 2019

Status

approved