A099249 Number of numbers not greater than n such that length in binary representation and number of ones are coprime.

1, 2, 2, 3, 4, 5, 5, 6, 6, 6, 7, 7, 8, 9, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 24, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 25, 26, 26, 26, 26, 26, 26, 26, 26, 27, 27, 27, 27, 28, 28, 29, 30, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41

Offset

1,2

Comments

Number of numbers m <= n such that A099244(m) = 1.

Links

Reinhard Zumkeller, Table of n, a(n) for n = 1..10000

Index entries for sequences related to binary expansion of n.

Formula

a(n) = Sum_{k=1..n} A063524(A099244(k)). - Reinhard Zumkeller, Oct 10 2013

Mathematica

Accumulate[Table[Boole[CoprimeQ[BitLength[n], DigitCount[n, 2, 1]]], {n, 1, 100}]] (* Amiram Eldar, Jul 16 2023 *)

Prog

(Haskell)
a099249 n = a099249_list !! (n-1)
a099249_list = scanl1 (+) $ map ((0 ^) . (subtract 1)) a099244_list
-- Reinhard Zumkeller, Oct 10 2013
(PARI) isA099247(k) = {my(b = binary(k)); gcd(#b, vecsum(b)) == 1; }
list(nmax) = {my(c = 0); for(n = 1, nmax, if(isA099247(n), c++); print1(c, ", ")); } \\ Amiram Eldar, Jul 26 2025

Crossrefs

Cf. A000120, A007088, A063524, A070939, A099244, A099247.

Sequence in context: A136378 A344374 A305557 * A050296 A057062 A283993

Adjacent sequences: A099246 A099247 A099248 * A099250 A099251 A099252

Keyword

nonn,base

Author

Reinhard Zumkeller, Oct 08 2004

Status

approved