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A153077 Largest number m such that sigma(m) = A002110(n) where A002110(n) is the product of the first n primes. 3

%I #16 Jul 19 2016 16:26:12

%S 5,29,116,2309,30029,272264,6715161,154448901,3696967556,126321788241,

%T 5984466237725,304250263527209,7475863618097156,495878856926202725,

%U 17521052944725830450,1749278213298193453469,65483587607609351045025

%N Largest 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="/A153077/b153077.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) = A057637(A002110(n)). - Chandler

%F a(A057704(n)) = A002110(A057704(n)) - 1. - _Ray Chandler_

%e a(9) = 154448901. Sigma(154448901) = A002110(9) = 223092870 = 2*3*5*7*11*13*17*19*23.

%Y Cf. A000203, A002110, A153076, A153078.

%K nonn

%O 2,1

%A _Donovan Johnson_, Dec 19 2008

%E Extended by _Ray Chandler_, Dec 28 2008

%E Terms a(22)-a(24) in b-file from _Max Alekseyev_, Jan 29 2012

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Last modified April 16 07:57 EDT 2024. Contains 371698 sequences. (Running on oeis4.)