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 A055094 Binary encoding of quadratic residue set of n. L(1/n) is the most significant bit, L(n-1/n) is the least significant bit, i.e., the rows of A055088 interpreted as binary numbers. 10
 0, 1, 2, 4, 9, 22, 52, 72, 146, 313, 738, 1156, 2829, 6772, 9520, 18496, 53643, 75154, 162438, 312328, 600116, 1513186, 4023888, 4737152, 9741609, 23182093, 38478994, 76286020, 166236537, 311977264, 921787428, 1212203072, 2962424994 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS L(a/n) stands for generalized Legendre symbol, with value = 1 only if a is a quadratic residue of n. LINKS FORMULA a(n) = qrs2bincode(n) MAPLE A055094 := proc(n)     local i, z;     z := 0;     for i from 1 to n-1 do         z := z*2;         if (1 = numtheory[quadres](i, n)) then             z := z + 1;         fi;     od;     return z; end proc: MATHEMATICA a[n_] := With[{rr = Table[Mod[k^2, n], {k, 1, n - 1}] // Union}, Boole[ MemberQ[rr, #]]& /@ Range[n - 1]] // FromDigits[#, 2]&; Array[a, 40] (* Jean-François Alcover, Mar 05 2016*) PROG (PARI) {a(n)=sum(k=1, n-1, 2^(k-1)*(0

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Last modified January 19 14:53 EST 2020. Contains 331049 sequences. (Running on oeis4.)