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 #10 Jan 19 2023 22:35:22
%S 1,4,6,12,64,24,60,4096,192,144,180,240,360,960,720,1073741824,840,
%T 1260,786432,36864,1680,2880,15360,2520,6300,6720,2359296,5040,
%U 3221225472,14400,983040,10080,206158430208,184320,15120,20160,25200
%N Smallest integer with A002191(n) divisors, i.e., the number of divisors equals the sum of the divisors of a different number.
%F A000005(a(n)) = A002191(n). I.e., if function A000005 is applied to this sequence, then values of A002191 are obtained. These terms are taken from A005179.
%F a(n) = A005179(A002191(n)). - _David Wasserman_, Jun 06 2002
%e For all values of sigma(x), i.e., of A002191, the smallest number with identical number of divisors is found at A005179(sigma(x)). E.g., 8 = A002191(6) is a possible divisor sum. The smallest number which has 8 divisors is 24 = A005179(8). See also comment to A008864, with special solutions of equation: sigma(x) = tau(y) = A000203(x) = A000005(y).
%Y Cf. A000005, A000203, A002191, A005179, A008864.
%K nonn
%O 1,2
%A _Labos Elemer_, May 28 2001
%E More terms from _David Wasserman_, Jun 06 2002
%E Offset corrected by _Sean A. Irvine_, Jan 19 2023