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Numbers n such that A145768(n) is a square.
7

%I #22 Apr 11 2021 04:24:23

%S 0,1,7,9,14,15,16,24,33,63,89,193,240,255,271,430,448,528,575,729,742,

%T 783,903,1297,1776,2409,2623,3494,4079,4159,5439,8278,13631,13737,

%U 16128,41825,53007,64344,95985,99015,100607,138238,147734,198976,256177,262079,262335,278847

%N Numbers n such that A145768(n) is a square.

%o (PARI) an=0;for(i=1,10^5,an=bitxor(an,i^2);issquare(an)&print1(i","))

%o (Python)

%o import math

%o x = 0

%o for i in range(1<<20):

%o x ^= i*i

%o t = int(math.sqrt(x))

%o if x == t*t:

%o print(str(i), end=', ')

%o # _Alex Ratushnyak_, Mar 27 2013

%Y A145828 = A145768 intersect A000290 = { A145768(a(n)) }.

%K easy,base,nonn

%O 1,3

%A _M. F. Hasler_, Oct 20 2008

%E More terms from _Alex Ratushnyak_, Mar 27 2013