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A212314 Numbers m such that B(m^3) = B(m)*3, where B(m) is the binary weight of m (A000120). 1
0, 5, 9, 10, 17, 18, 20, 33, 34, 36, 39, 40, 49, 65, 66, 68, 69, 72, 78, 80, 98, 105, 129, 130, 132, 135, 136, 138, 144, 156, 160, 169, 196, 199, 209, 210, 229, 257, 258, 260, 263, 264, 270, 272, 276, 277, 288, 291, 297, 312, 313, 320, 338, 359, 365, 392, 395, 398, 418 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..59.

FORMULA

A000120(a(n)^3) = A000120(a(n)) * 3.

PROG

(Python)

import math

for n in range(10000):

    c1 = c2 = 0

    t = n

    while t:

        c1+=t&1

        t>>=1

    t = n*n*n

    while t:

        c2+=t&1

        t>>=1

    if c1*3==c2: print(str(n), end=', ')

(Sage)

s = lambda n: sum((n^3).digits(2)) - 3*sum(n.digits(2))

[n for n in (0..418) if s(n)==0]  # Peter Luschny, Oct 24 2013

CROSSREFS

Cf. A000120, A077436, A083567, A118655, A212315.

Sequence in context: A155470 A266399 A164709 * A136318 A242139 A216765

Adjacent sequences:  A212311 A212312 A212313 * A212315 A212316 A212317

KEYWORD

nonn,base,easy

AUTHOR

Alex Ratushnyak, Oct 24 2013

STATUS

approved

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Last modified December 3 18:19 EST 2021. Contains 349467 sequences. (Running on oeis4.)