A247142 Numbers for which the root mean square of proper divisors is an integer.
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 35, 37, 41, 43, 47, 49, 53, 55, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 145, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199, 211, 215, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 283, 293, 307, 311, 313, 317, 331, 337, 341
Offset: 1
Keywords
Links
- Daniel Lignon, Table of n, a(n) for n = 1..1249
Crossrefs
Cf. A140480 (RMS of all divisors is an integer).
Programs
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Mathematica
Select[Range[2,1000],IntegerQ[RootMeanSquare[Most[Divisors[#]]]]&]
Comments