A153077 - OEIS

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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.

5, 29, 116, 2309, 30029, 272264, 6715161, 154448901, 3696967556, 126321788241, 5984466237725, 304250263527209, 7475863618097156, 495878856926202725, 17521052944725830450, 1749278213298193453469, 65483587607609351045025

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OFFSET

2,1

LINKS

Ray Chandler, Max Alekseyev, Table of n, a(n) for n = 2..24

Max A. Alekseyev, Computing the Inverses, their Power Sums, and Extrema for Euler's Totient and Other Multiplicative Functions. Journal of Integer Sequences, Vol. 19 (2016), Article 16.5.2

FORMULA

a(n) = A057637(A002110(n)). - Chandler

a(A057704(n)) = A002110(A057704(n)) - 1. - Ray Chandler

EXAMPLE

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

CROSSREFS