A153076 - OEIS

%I #16 Jul 19 2016 16:24:53

%S 5,29,104,1538,13842,188424,3249576,101864576,2388809736,59720243400,

%T 2571228006912,85266458294400,6038197537693842,227036227417289064,

%U 12129959730964036050,606111287080086323712,36186481977293685109248

%N Smallest number m such that sigma(m) = A002110(n) where A002110(n) is the product of the first n primes.

%H Ray Chandler, Max Alekseyev, <a href="/A153076/b153076.txt">Table of n, a(n) for n = 2..24</a>

%H Max A. Alekseyev, <a href="https://www.emis.de/journals/JIS/VOL19/Alekseyev/alek5.html">Computing the Inverses, their Power Sums, and Extrema for Euler's Totient and Other Multiplicative Functions</a>. Journal of Integer Sequences, Vol. 19 (2016), Article 16.5.2

%F a(n) = A051444(A002110(n)). - _Ray Chandler_

%e a(9) = 101864576. Sigma(101864576) = A002110(9) = 223092870 = 2*3*5*7*11*13*17*19*23.

%Y Cf. A000203, A002110, A153077, A153078.

%K nonn

%O 2,1

%A _Donovan Johnson_, Dec 19 2008

%E Extended by _Ray Chandler_, Dec 28 2008

%E a(22)-a(24) added to b-file by _Max Alekseyev_, Jan 31 2012