OFFSET

1,1

COMMENTS

LINKS

Amiram Eldar, Table of n, a(n) for n = 1..470

Lawrence C. Washington and Ambrose Yang, Analogues of the Robin-Lagarias criteria for the Riemann hypothesis, International Journal of Number Theory, Vol. 17, No. 4 (2021), pp. 843-870; arXiv preprint, arXiv:2008.04787 [math.NT], 2020.

EXAMPLE

3 is in the sequence since 3 is odd and sigma(3) = 4 > exp(gamma) * 3 * log(log(3))/2 = 0.251... .

MATHEMATICA

Select[Range[3, 600, 2], DivisorSigma[1, #] > Exp[EulerGamma] * # * Log[Log[#]]/2 &]

PROG

(Python) from sympy import divisor_sigma, EulerGamma, E, log

print([k for k in range(3, 600, 2) if divisor_sigma(k) > (E**EulerGamma * k * log(log(k)) / 2)]) # Karl-Heinz Hofmann, Apr 22 2022

CROSSREFS

KEYWORD

nonn

AUTHOR

Amiram Eldar, Apr 22 2022

STATUS

approved