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A343219
a(n) = 1 if A003415(sigma(k)) > k, otherwise 0.
4
0, 0, 1, 0, 0, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1
OFFSET
1
MATHEMATICA
Array[Boole[If[#2 < 2, 0, #2 Total[#2/#1 & @@@ FactorInteger[#2]]] > #1] & @@ {#, DivisorSigma[1, #]} &, 105] (* Michael De Vlieger, Apr 08 2021 *)
PROG
(PARI)
A003415(n) = if(n<=1, 0, my(f=factor(n)); n*sum(i=1, #f~, f[i, 2]/f[i, 1]));
A343219(n) = (A003415(sigma(n))>n);
CROSSREFS
Characteristic function of A343218.
Sequence in context: A308901 A286804 A188071 * A189640 A289057 A106138
KEYWORD
nonn
AUTHOR
Antti Karttunen, Apr 08 2021
STATUS
approved