A247137 Numbers for which the root mean square of nontrivial divisors is an integer and which are not a square of prime numbers.
119, 161, 343, 369, 527, 711, 721, 833, 959, 1081, 1127, 1241, 1695, 1767, 2047, 3281, 3335, 3553, 3713, 4207, 4633, 4681, 5047, 5215, 6713, 6887, 7327, 7775, 9641, 12319, 14031, 16617, 16999, 18473, 19199, 22145, 27009, 27913, 29449, 31679, 32239, 32599, 37241, 44801, 45385, 47865, 47959, 50279, 52319, 56033
Offset: 1
Keywords
Links
- Daniel Lignon and Charles R Greathouse IV, Table of n, a(n) for n = 1..10000 (terms up to 148 from Lignon)
Crossrefs
Cf. A247136 (Numbers for which the root mean square of nontrivial divisors is an integer).
Programs
-
PARI
integralRMS(v)=my(t=norml2(v)/#v); denominator(t)==1 && issquare(t) is(n)=my(d=divisors(n)); #d>3 && integralRMS(d[2..#d-1]) \\ Charles R Greathouse IV, Nov 20 2014
Comments