A324906 Number of trailing 1-bits in the binary representation of A318466(n), where A318466(n) = 2*n OR sigma(n).

2, 3, 0, 4, 0, 0, 0, 5, 5, 0, 0, 0, 0, 0, 0, 6, 0, 3, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 1, 0, 0, 0, 0, 0

Offset

1,1

Links

Antti Karttunen, Table of n, a(n) for n = 1..65537

Index entries for sequences related to binary expansion of n

Index entries for sequences related to sigma(n)

Formula

a(n) = A007814(1+A318466(n)).

Mathematica

Array[LengthWhile[Reverse@ IntegerDigits[BitOr[2 #, DivisorSigma[1, #]], 2], # == 1 &] &, 105] (* Michael De Vlieger, Mar 30 2019 *)

Prog

(PARI)
A318466(n) = bitor(2*n, sigma(n));
A324906(n) = valuation(1+A318466(n), 2);
(Python)
from sympy import divisor_sigma
def A324906(n): return ((m:=(n<<1)|int(divisor_sigma(n)))&~(m+1)).bit_length() # Chai Wah Wu, Jul 10 2022

Crossrefs

Cf. A000203, A003986, A007814, A318466, A324904, A324908.

Sequence in context: A161628 A244119 A122059 * A164917 A166238 A293275

Adjacent sequences: A324903 A324904 A324905 * A324907 A324908 A324909

Keyword

nonn

Author

Antti Karttunen, Mar 28 2019

Status

approved