OFFSET
1,1
COMMENTS
5040 is the last element in the sequence if and only if the Riemann Hypothesis is true. (See Akbary and Friggstad in A004394.)
LINKS
G. Caveney, J.-L. Nicolas, and J. Sondow, Robin's theorem, primes, and a new elementary reformulation of the Riemann Hypothesis, Integers 11 (2011), #A33 (see Table 1).
G. Caveney, J.-L. Nicolas and J. Sondow, On SA, CA, and GA numbers, arXiv:1112.6010 [math.NT], 2011-2012; Ramanujan J., 29 (2012), 359-384.
MATHEMATICA
PROG
(PARI) is(n)=sigma(n) >= exp(Euler) * n * log(log(n)); \\ A067698
lista(nn) = my(r=1, t); forstep(n=2, nn, 2, t=sigma(n, -1); if(t>r && is(n), r=t; print1(n, ", "))); \\ Michel Marcus, Jan 28 2019; adapted from A004394
CROSSREFS
KEYWORD
nonn
AUTHOR
Geoffrey Caveney, Jean-Louis Nicolas, and Jonathan Sondow, May 30 2011
EXTENSIONS
Erroneous terms 1260 and 1680 removed by Jean-François Alcover, Jan 28 2019
STATUS
approved