cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A080146 Binary encoding of quadratic residue set for each prime. a(n) = A055094(A000040(n)).

Original entry on oeis.org

1, 2, 9, 52, 738, 2829, 53643, 162438, 4023888, 166236537, 921787428, 48034254669, 935251837851, 2558696229078, 68055676507664, 2655011771373417, 210067141980993186, 831463105466530077, 42882922858578320598
Offset: 1

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Author

Antti Karttunen, Feb 11 2003

Keywords

Crossrefs

Programs

  • Maple
    with(numtheory,ithprime); A080146 := n -> A055094(ithprime(n));
  • Mathematica
    A055094[n_] := With[{rr = Table[Mod[k^2, n], {k, 1, n-1}] // Union}, Boole[MemberQ[rr, #]]& /@ Range[n-1]] // FromDigits[#, 2]&;
    a[n_] := A055094[Prime[n]];
    Table[a[n], {n, 1, 20}] (* Jean-François Alcover, Sep 20 2022 *)
  • PARI
    a(n) = my(p=prime(n)); sum(k=1, p-1, 2^(k-1)*(0Michel Marcus, Sep 20 2022; after A055094

Formula

a(A080148(n)) = A080117(A080148(n)).