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A221643 Numbers k such that k^2 XOR (k+1)^2 is a square, where XOR is the bitwise XOR operator. 7
0, 3, 4, 23, 24, 43, 44, 76, 111, 112, 115, 139, 164, 180, 183, 248, 264, 323, 327, 348, 411, 479, 480, 499, 611, 699, 747, 787, 943, 976, 1072, 1103, 1111, 1176, 1268, 1388, 1447, 1576, 1684, 1851, 1983, 1984, 2008, 2243, 2692, 3271, 3383, 3452, 3464, 3532, 3679, 3804, 3867 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..53.

PROG

(Python)

import math

for i in range(1<<16):

    s = (i*i) ^ ((i+1)*(i+1))

    t = int(math.sqrt(s))

    if s == t*t:

        print(str(i), end=', ')

CROSSREFS

Cf. A145827, A001737.

Sequence in context: A316192 A122660 A163744 * A042595 A002351 A042035

Adjacent sequences:  A221640 A221641 A221642 * A221644 A221645 A221646

KEYWORD

nonn,base

AUTHOR

Alex Ratushnyak, Mar 27 2013

STATUS

approved

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Last modified May 28 22:08 EDT 2022. Contains 354122 sequences. (Running on oeis4.)