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A224511 Roots of squares generated in A221643. That is, S = i^2 XOR (i+1)^2; increment i; if S is a square then square root of S is appended to a(n). Initially i=0. XOR is the binary logical exclusive-or operator. 1
1, 5, 3, 9, 7, 13, 11, 21, 17, 15, 43, 45, 29, 19, 41, 25, 23, 59, 39, 27, 35, 33, 31, 85, 37, 61, 51, 53, 47, 81, 79, 49, 55, 121, 83, 75, 57, 73, 77, 67, 65, 63, 71, 69, 125, 89, 87, 123, 105, 107, 95, 101, 163, 93, 91, 99, 97, 349, 243, 103, 169, 109, 233, 115, 119, 171 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Conjecture: this is a permutation of odd numbers.

b(n) = (a(n)-1)/2  begins: 0, 2, 1, 4, 3, 6, 5, 10, 8, 7, 21, 22, 14, 9, 20, 12, 11, 29, 19, 13, 17.

LINKS

Table of n, a(n) for n=1..66.

PROG

(Python)

import math

for i in range(1<<16):

    s = (i*i) ^ ((i+1)*(i+1))

    r = int(math.sqrt(s));

    if s == r*r:

        print str(r)+', ',

CROSSREFS

Cf. A221643, A224515.

Sequence in context: A073891 A196396 A086970 * A201938 A201410 A019955

Adjacent sequences:  A224508 A224509 A224510 * A224512 A224513 A224514

KEYWORD

nonn,base,less,changed

AUTHOR

Alex Ratushnyak, Apr 08 2013

STATUS

approved

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Last modified December 15 04:23 EST 2019. Contains 329991 sequences. (Running on oeis4.)