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A112058
Mean of A112056 and A112057.
4
48, 72, 120, 168, 192, 288, 312, 360, 408, 432, 480, 528, 552, 648, 672, 720, 768, 792, 840, 888, 912, 960, 1008, 1032, 1128, 1152, 1200, 1248, 1272, 1320, 1368, 1392, 1488, 1512, 1560, 1608, 1632, 1680, 1728, 1752, 1800, 1848, 1872, 1968
OFFSET
1,1
FORMULA
a(n) = 4*A112054(n).
MATHEMATICA
a112046[n_]:=Block[{i=1}, While[JacobiSymbol[i, 2n + 1]==1, i++]; i]; 4*Select[Range[1000], a112046[2#] - a112046[2# - 1] != 0 &] (* Indranil Ghosh, May 24 2017 *)
PROG
(Python)
from sympy import jacobi_symbol as J
def a112046(n):
i=1
while True:
if J(i, 2*n + 1)!=1: return i
else: i+=1
def a(n): return a112046(2*n) - a112046(2*n - 1)
print([4*n for n in range(1, 1001) if a(n)!=0]) # Indranil Ghosh, May 24 2017
CROSSREFS
a(n) = A112056(n)+1 = A112057(n)-1 = (A112056(n)+A112057(n))/2.
Sequence in context: A173042 A309933 A124309 * A033821 A334899 A165039
KEYWORD
nonn
AUTHOR
Antti Karttunen, Aug 27 2005
STATUS
approved