A353046 Odd values that are not attained by A332775(m) = m + sopf(m) - omega(m) when m runs over the natural numbers.
7, 19, 23, 31, 41, 43, 47, 49, 59, 89, 91, 101, 103, 107, 113, 137, 139, 143, 161, 167, 169, 175, 179, 199, 209, 227, 229, 233, 239, 241, 243, 251, 259, 263, 271, 275, 281, 283, 287, 299, 315, 319, 329, 337, 343, 353, 359, 377, 407, 419, 443, 451, 459, 461, 463, 467, 473, 475, 479, 491
Offset: 1
Keywords
Examples
A332775(4) = 5, hence 5 is not a term. There is no k such that A332775(k) = 7, and 7 is the least integer that is not attained, hence a(1) = 7.
Programs
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Mathematica
f[n_] := n + Plus @@ (FactorInteger[n][[;;,1]] - 1); m = 500; Complement[Range[1, m, 2], Array[f, m]] (* Amiram Eldar, Apr 20 2022 *)
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PARI
f(n) = n + vecsum(factor(n)[, 1]) - omega(n); \\ A332775 lista(nn) = setminus(Set(select(x->(x%2), [1..nn])), Set(vector(nextprime(2*nn), k, f(k)))); \\ Michel Marcus, Apr 20 2022
Extensions
More terms from Michel Marcus, Apr 20 2022
Comments