A331206 Numbers k such that A053985(k) divides k.

1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 17, 20, 21, 24, 30, 32, 34, 40, 42, 48, 51, 60, 63, 64, 65, 68, 69, 80, 81, 84, 85, 96, 102, 120, 126, 128, 130, 136, 138, 160, 162, 168, 170, 192, 195, 204, 207, 240, 243, 252, 255, 256, 257, 260, 261, 272, 273, 276, 277

Offset

1,2

Comments

It appears that A053985(a(n)) / a(n) is always either 1, -1, 3 or -3.

This sequence seems to contain A329000.

Links

Table of n, a(n) for n=1..60.

Example

15 is written 1111 base 2 and (-2)^3 + (-2)^2 + (-2)^1 +(-2)^0 = -8 + 4 - 2 + 1 = -5, 15 is divisible by -5.

Prog

(PARI) is(k) = k%fromdigits(binary(k), -2) == 0; \\ Jinyuan Wang, Jan 15 2020

Crossrefs

Sequence in context: A182418 A204580 A347831 * A295298 A003401 A281624

Adjacent sequences: A331203 A331204 A331205 * A331207 A331208 A331209

Keyword

nonn,base

Author

Alon Ran, Jan 12 2020

Status

approved