A217867 Extremely abundant numbers: a(1)=10080; thereafter a(n) is a term if for n > m >= 1, sigma(a(n))/(a(n) log log a(n)) > sigma(a(m))/(a(m)log log a(m)).

10080, 8201519488959040182625924708238885435575055666675808000, 1041592975097798103193492437946338450318032069667827616000, 136448679737811551518347509370970336991662201126485417696000, 18693469124080182558013608783822936167857721554328502224352000, 2598392208247145375563891620951388127332223296051661809184928000, 5196784416494290751127783241902776254664446592103323618369856000

Offset

1,1

Comments

If a(n) is an extremely abundant number, then it is superabundant.

Links

T. D. Noe, Table of n, a(n) for n = 1..156

Sadegh Nazardonyavi, Extremely abundant number

S. Nazardonyavi, S. Yakubovich, Extremely Abundant Numbers and the Riemann Hypothesis, Journal of Integer Sequences, 17 (2014), Article 14.2.8.

Crossrefs

A subset of A004394, A004490.

Sequence in context: A145836 A190293 A179729 * A157288 A230033 A252052

Adjacent sequences: A217864 A217865 A217866 * A217868 A217869 A217870

Keyword

nonn

Author

Sadegh Nazardonyavi, Oct 27 2012

Status

approved