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.

A029886 Convolution of Thue-Morse sequence A001285 with itself.

Original entry on oeis.org

1, 4, 8, 10, 12, 14, 15, 16, 22, 24, 23, 26, 29, 30, 34, 40, 38, 40, 43, 42, 47, 50, 52, 56, 55, 56, 62, 66, 64, 70, 71, 64, 78, 80, 75, 82, 83, 82, 88, 96, 89, 92, 100, 98, 102, 106, 105, 104, 111, 112, 114, 122, 118, 122, 125, 120, 130, 136, 131, 130, 141, 134, 138, 160
Offset: 0

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Author

Keywords

Comments

Comment from Jeremy Gardiner, Dec 28 2008: The following sequences all appear to have the same parity: A003071, A029886, A061297, A092524, A093431, A102393, A104258, A122248, A128975.

Crossrefs

Cf. A001285.

Programs

  • Mathematica
    P[n_, x_] := (bb = IntegerDigits[n, 2]) . x^Range[Length[bb]-1, 0, -1];
    TM[n_] := 1 + Mod[P[n, 1], 2];
    a[n_] := Sum[TM[k] TM[n-k], {k, 0, n}];
    Table[a[n], {n, 0, 63}] (* Jean-François Alcover, Aug 31 2018 *)
  • PARI
    a(n)=sum(k=0,n,(1+subst(Pol(binary(k)),x,1)%2)*(1+subst(Pol(binary(n-k)),x,1)%2)) \\ Ralf Stephan, Aug 23 2013

Formula

G.f.: (1/4)*(3/(1 - x) - Product_{k>=0} (1 - x^(2^k)))^2. - Ilya Gutkovskiy, Apr 03 2019