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a(n) = A112046(2n) - A112046(2n-1) = A112048(n) - A112047(n).
6

%I #13 Apr 28 2021 10:11:04

%S 0,0,0,0,0,0,0,0,0,0,0,2,0,0,0,0,0,-2,0,0,0,0,0,0,0,0,0,0,0,4,0,0,0,0,

%T 0,0,0,0,0,0,0,8,0,0,0,0,0,-2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

%U 0,0,0,12,0,0,0,0,0,-6,0,0,0,0,0,0,0,0,0,0,0,12,0,0,0,0,0,0,0,0,0,0,0

%N a(n) = A112046(2n) - A112046(2n-1) = A112048(n) - A112047(n).

%H Antti Karttunen, <a href="/A112053/b112053.txt">Table of n, a(n) for n = 1..10000</a>

%F a(n) = A112048(n)-A112047(n).

%t a112046[n_]:=Block[{i=1}, While[JacobiSymbol[i, 2n + 1]==1, i++]; i]; Table[a112046[2n] - a112046[2n - 1] , {n, 101}] (* _Indranil Ghosh_, May 24 2017 *)

%o (Python)

%o from sympy import jacobi_symbol as J

%o def a112046(n):

%o i=1

%o while True:

%o if J(i, 2*n + 1)!=1: return i

%o else: i+=1

%o def a(n): return a112046(2*n) - a112046(2*n - 1)

%o print([a(n) for n in range(1, 102)]) # _Indranil Ghosh_, May 24 2017

%Y Cf. A112046, A112047, A112048.

%Y Indices where a(n) is not zero: A112054. Values at those points: A112059.

%K sign

%O 1,12

%A _Antti Karttunen_, Aug 27 2005