%I #7 Jul 28 2015 05:36:13
%S 6,28,120,496,672,8128,30240,33550336,8589869056,137438691328
%N Numbers n such that A000203(n) == n*A001221(n).
%C Subsequence of A007691.
%C a(n) is in A000396 iff A001221(a(n)) == 2, i.e., if a(n) is in A007774.
%C a(11) > 2.5*10^12. - _Giovanni Resta_, Jul 28 2015
%o (PARI) is(n) = sigma(n)==n*omega(n)
%Y Cf. A000396, A007691.
%K nonn,more
%O 1,1
%A _Felix Fröhlich_, Jul 27 2015
%E a(9)-a(10) from _Giovanni Resta_, Jul 28 2015
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