OFFSET
1,2
LINKS
Carole Dubois, Table of n, a(n) for n = 1..5005
EXAMPLE
a(1) = 1 is divisible by the digital root of 10 (which is 1 + 0 = 1);
a(2) = 10 is divisible by the dig. root of 2 (which is = 2);
a(3) = 2 is divisible by the dig. root of 11 (which is 1 + 1 = 2);
a(4) = 11 is divisible by the dig. root of 19 (which is 1 + 9 = 10 => 1 + 0 = 1);
a(5) = 19 is divisible by the dig. root of 28 (which is 2 + 8 = 10 => 1 + 0 = 1);
a(6) = 28 is divisible by the dig. root of 4 (which is = 4); etc.
CROSSREFS
KEYWORD
base,nonn
AUTHOR
Eric Angelini and Carole Dubois, May 09 2020
STATUS
approved