OFFSET
1,1
COMMENTS
Records are a(1) = 5, a(2) = 33, a(11) = 55, a(14) = 141, a(26) = 177, a(34) = 212, a(47) = 235, a(53) = 265, a(93) = 285, a(98) = 366, a(102) = 442, a(107) = 535, a(158) = 902, a(166) = 2739, a(758) = 3424, a(863) = 4315, a(866) = 4470, a(1171) = 5855, a(1478) = 6790, a(1493) = 7465, a(1823) = 9115, a(2203) = 11015, a(3463) = 14795, a(3833) = 19165, a(6459) = 19379, a(6865) = 20257, a(7926) = 22918, a(9938) = 23161, .... - Charles R Greathouse IV, Jul 21 2016
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..10000
EXAMPLE
a(1) = 5 because sigma(5) / tau(5) = (1 + 5) / 2 = 3 and sigma(6) / tau(6) = (1 + 2 + 3 + 6) / 4 = 3.
PROG
(PARI) avdiv(n)=my(f=factor(n)); sigma(f)/numdiv(f)
a(n)=my(k=1); while(avdiv(k) != avdiv(k+n), k++); k \\ Charles R Greathouse IV, Jul 21 2016
CROSSREFS
KEYWORD
nonn
AUTHOR
Altug Alkan, Jul 20 2016
STATUS
approved