Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #8 Aug 31 2019 15:33:10
%S 1,2,4,6,8,16,32,40,64,128,224,256,264,512,1024,2048,4096,5632,8192,
%T 16384,26624,32768,65536,72192,131072,154752,262144,524288,557056,
%U 1048576,2072576,2097152,2490368,4194304,5537792,8388608,10518528,16777216,33554432,48234496
%N Numbers n such that A067824(n) = n.
%H Amiram Eldar, <a href="/A122408/b122408.txt">Table of n, a(n) for n = 1..100</a>
%F A002033(a(n)) = A074206(a(n)) = a(n)/2.
%F A067824(a(n)) = a(n).
%e m=40, the proper divisors of 40 are 1, 2, 4, 5, 8, 10 and 20:
%e A067824(40) = 1+Sum(A067824(d): 1<=d<40) = 1+(1+2+4+2+8+6+16) = 40, therefore 40 is a term.
%Y A000079 is a subsequence.
%Y Cf. A002033, A067824, A074206, A163272.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Sep 03 2006
%E More terms from _Amiram Eldar_, Aug 31 2019