A103449 Values of k such that Sum_{m=0..k} Moebius(binomial(k,m)) = 0.
3, 12, 24, 29, 34, 40, 54, 60, 67, 68, 75, 86, 93, 97, 102, 119, 125, 131, 133, 142, 152, 157, 160, 163, 164, 168, 170, 172, 189, 193, 197, 208, 210, 220, 221, 228, 229, 246, 251, 255, 257, 261, 270, 275, 280, 293, 296, 307, 308, 313, 315, 332, 337, 338, 340
Offset: 1
Keywords
Examples
12 belongs to the sequence because the only squarefree values of binomial(12,m) are 1, 2*3*11, 2*3*11, 1, on which the Mobius function takes the values 1,-1,-1,1, respectively. 8 does not belong to the sequence because the only squarefree value of binomial(8,m) are 1, 2*5*7, 1, on which the Moebius function takes the values 1,-1,1, respectively.
Links
- G. C. Greubel, Table of n, a(n) for n = 1..1000
Programs
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Mathematica
A103448[n_]:= A103448[n]= Sum[MoebiusMu[Binomial[n, k]], {k, 0, n}]; f:= Table[A103448[n], {n, 0, 1050}]; Select[Range[0, 1000], f[[#]] == 0 &] - 1 (* G. C. Greubel, Jun 17 2021 *)
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PARI
is(k) = sum(m=0, k, moebius(binomial(k, m)))==0 \\ Felix Fröhlich, Jun 18 2021
Comments