A338453 Starts of runs of 3 consecutive numbers with the same total binary weight of their divisors (A093653).

3, 242, 243, 1837, 2361, 3693, 3728, 6061, 6457, 9782, 11181, 11721, 13855, 15177, 20017, 22591, 28021, 31461, 31887, 33098, 33993, 38137, 52016, 52112, 60321, 76897, 78542, 78745, 80461, 108394, 116017, 119541, 124453, 125493, 127117, 127417, 145369, 151805, 154113

Offset

1,1

Comments

Numbers k such that A093653(k) = A093653(k+1) = A093653(k+2).

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

3 is a term since A093653(3) = A093653(4) = A093653(5) = 3.

Mathematica

f[n_] := DivisorSum[n, DigitCount[#, 2, 1] &]; s = {}; m = 3; fs = f /@ Range[m]; Do[If[Equal @@  fs, AppendTo[s, n - m]]; fs = Rest @ AppendTo[fs, f[n]], {n, m + 1, 155000}]; s
SequencePosition[Table[Total[DigitCount[Divisors[n], 2, 1]], {n, 160000}], {x_, x_, x_}][[All, 1]] (* Harvey P. Dale, Feb 04 2023 *)

Crossrefs

Cf. A093653.

Subsequence of A338452.

Similar sequences: A005238, A006073, A045939.

Sequence in context: A069640 A324444 A236249 * A013778 A146313 A092799

Adjacent sequences: A338450 A338451 A338452 * A338454 A338455 A338456

Keyword

nonn,base

Author

Amiram Eldar, Oct 28 2020

Status

approved