A379040 Fixed points in A379015.

0, 1, 5, 9, 13, 17, 21, 33, 45, 57, 65, 73, 85, 93, 129, 165, 173, 189, 205, 217, 241, 257, 273, 297, 309, 325, 341, 381, 441, 513, 585, 645, 685, 733, 765, 797, 845, 857, 889, 921, 945, 993, 1025, 1057, 1105, 1129, 1161, 1193, 1205, 1253, 1285, 1317, 1365, 1389

Offset

1,3

Comments

Such points exist when the non-adjacent form representation of n is palindromic.

Links

Table of n, a(n) for n=1..54.

Wikipedia, Non-adjacent form.

Prog

(Python)
def isok(n):
    E, r = n, 0
    while E:
        if E & 1:
            Zi = 2 - (E & 3)
            E -= Zi
            r += Zi
        E >>= 1
        r <<= 1
    return (r >> 1) == n
print([n for n in range(0, 1400) if isok(n)])

Crossrefs

Cf. A379015.

Sequence in context: A291180 A057948 A314682 * A004958 A190887 A314683

Adjacent sequences: A379037 A379038 A379039 * A379041 A379042 A379043

Keyword

nonn,base

Author

Darío Clavijo, Dec 14 2024

Extensions

Leading 0 added by Rémy Sigrist, Dec 28 2024

Status

approved