A153077 -id:A153077 - cp's OEIS frontend

A153076 Smallest number m such that sigma(m) = A002110(n) where A002110(n) is the product of the first n primes.

5, 29, 104, 1538, 13842, 188424, 3249576, 101864576, 2388809736, 59720243400, 2571228006912, 85266458294400, 6038197537693842, 227036227417289064, 12129959730964036050, 606111287080086323712, 36186481977293685109248

Offset: 2

Donovan Johnson, Dec 19 2008

nonn

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

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

Cf. A000203, A002110, A153077, A153078.

a(n) = A051444(A002110(n)). - Ray Chandler

Extended by Ray Chandler, Dec 28 2008

a(22)-a(24) added to b-file by Max Alekseyev, Jan 31 2012

A153078 Number of values of m such that sigma(m) = A002110(n) where A002110(n) is the product of the first n primes.

Original entry on oeis.org

0, 1, 1, 2, 2, 5, 2, 4, 5, 3, 7, 5, 10, 2, 8, 4, 5, 6, 11, 32, 42, 68, 24, 87

Offset: 1

Donovan Johnson, Dec 19 2008

			a(10) = 3 because 2388809736, 3450503048 and 3696967556 are the only numbers with a sigma value = A002110(10). A002110(10) = 6469693230 = 2*3*5*7*11*13*17*19*23*29.

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.

Cf. A000203, A002110, A153076, A153077.

a(n) = A054973(A002110(n)). - Ray Chandler, Dec 28 2008

a(12)-a(21) from Ray Chandler, Dec 28 2008

a(22)-a(24) from Max Alekseyev, Jan 27 2012

cp's OEIS Frontend

A153076 Smallest number m such that sigma(m) = A002110(n) where A002110(n) is the product of the first n primes.

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