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A267697 Numbers with 7 odd divisors. 7

%I

%S 729,1458,2916,5832,11664,15625,23328,31250,46656,62500,93312,117649,

%T 125000,186624,235298,250000,373248,470596,500000,746496,941192,

%U 1000000,1492992,1771561,1882384,2000000,2985984,3543122,3764768,4000000,4826809,5971968,7086244,7529536,8000000,9653618

%N Numbers with 7 odd divisors.

%C Positive integers that have exactly seven odd divisors.

%C Numbers n such that the symmetric representation of sigma(n) has 7 subparts. - _Omar E. Pol_, Dec 28 2016

%F A001227(a(n)) = 7.

%o (PARI) isok(n) = sumdiv(n, d, (d%2)) == 7; \\ _Michel Marcus_, Apr 03 2016

%Y Column 7 of A266531.

%Y Cf. A001227, A038547, A236104, A237593, A279387.

%Y Numbers with k odd divisors (k = 1..10): A000079, A038550, A072502, apparently A131651, A267696, A230577, this sequence, A267891, A267892, A267893.

%K nonn

%O 1,1

%A _Omar E. Pol_, Apr 03 2016

%E More terms from _Michel Marcus_, Apr 03 2016

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Last modified December 12 16:38 EST 2017. Contains 295949 sequences.