A348367 a(n) = w(n + w(n)), where w(n) is the binary weight of n, A000120(n).

1, 2, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 1, 2, 3, 2, 3, 2, 3, 3, 2, 3, 4, 3, 3, 4, 5, 5, 2, 2, 2, 2, 3, 2, 3, 3, 2, 3, 4, 3, 3, 4, 5, 5, 3, 3, 3, 3, 3, 4, 5, 5, 4, 4, 4, 5, 5, 5, 1, 1, 2, 3, 3, 2, 3, 2, 3, 3, 2, 3, 4, 3, 3, 4, 5, 5, 3, 3, 3, 3, 3, 4, 5, 5, 4, 4, 4, 5, 5, 5, 2, 2, 3, 4, 4, 3, 3, 4, 5

Offset

1,2

Links

Table of n, a(n) for n=1..99.

Formula

a(n) = A000120(n + A000120(n)); a(n) = A000120(A092391(n)).

Example

n = 5; a(5) = A000120(5 + A000120(5)) = 3.

Mathematica

h[n_] := DigitCount[n, 2, 1]; a[n_] := h[n + h[n]]; Array[a, 100] (* Amiram Eldar, Oct 15 2021 *)

Prog

(Python)
def h(n): return bin(n).count('1')
def a(n): return h(n + h(n))
print([a(n) for n in range(1, 100)]) # Michael S. Branicky, Oct 15 2021
(PARI) a(n) = hammingweight(n + hammingweight(n)); \\ Michel Marcus, Oct 17 2021

Crossrefs

Cf. A000120, A092391.

Sequence in context: A010244 A141298 A256915 * A209254 A227738 A103960

Adjacent sequences: A348364 A348365 A348366 * A348368 A348369 A348370

Keyword

nonn,base

Author

Ctibor O. Zizka, Oct 15 2021

Status

approved