OFFSET
1,1
COMMENTS
Since all multiples of 6 are abundant, numbers in this sequence have to be abundant numbers of the form 6n or 6n + 1. Most common difference between abundant numbers is 6, followed by 2, 4, 3, 1. 5 is the least common.
LINKS
David A. Corneth, Table of n, a(n) for n = 1..10000
FORMULA
Either a(n) or a(n)+5 are in A115414. - Amiram Eldar, Jul 16 2019
EXAMPLE
a(1) = 5391411025 is in the sequence since it is abundant and the next abundant number is 5391411030 which is a(1)+5 and all the numbers in between are deficient.
PROG
(PARI) isok(n) = for(k=1, 4, if(sigma(n+k) > 2*(n+k), return(0))); (sigma(n) > 2*n) && (sigma(n+5) > 2*(n+5)); \\ Daniel Suteu, Jul 24 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Sergio Pimentel, Feb 19 2019
EXTENSIONS
More terms from Amiram Eldar, Jul 16 2019
STATUS
approved