A339216 - OEIS

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

(list; graph; refs; listen; history; text; internal format)

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