A339216 Numbers k such that k and k+2 are both binary self numbers (A010061).

4, 13, 21, 30, 37, 46, 54, 78, 86, 95, 102, 111, 119, 128, 133, 142, 150, 159, 166, 175, 183, 207, 215, 224, 231, 240, 248, 270, 278, 287, 294, 303, 311, 335, 343, 352, 359, 368, 376, 385, 390, 399, 407, 416, 423, 432, 440, 464, 472, 481, 488, 497, 505, 526, 534

Offset

1,1

Comments

The least difference between consecutive binary self numbers is 2 (see Macris's proof at A010061).

Links

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

Example

4 is a term since 4 and 6 = 4 + 2 are both binary self numbers.

Mathematica

s[n_] := n + DigitCount[n, 2, 1]; m = 550; c = Complement[Range[m], Array[s, m]]; d = Differences[c]; ind = Position[d, 2] // Flatten; c[[ind]]

Crossrefs

Cf. A010061.

Sequence in context: A228138 A339271 A081024 * A155095 A063219 A063121

Adjacent sequences: A339213 A339214 A339215 * A339217 A339218 A339219

Keyword

nonn,base

Author

Amiram Eldar, Nov 27 2020

Status

approved