OFFSET
1,1
COMMENTS
a(n) with n>=3 is too large to be written in data.
The following is a method for finding a(n): Let n be the number of digits shifted, and let m be the smallest positive integer such that 10^m = 2 mod 2*10^n-1. We then look for the smallest positive b that is an n+d digit number and satisfies b = c(10^n-2)/(2*10^d-1), where c is a positive integer. Then a(n) = c(10^n-2)/(2*10^d-1)*10^n+c.
EXAMPLE
a(1) = 105263157894736842 because shifting the 1 rightmost digit to the left end gives 210526315789473684 which is double a(1).
CROSSREFS
KEYWORD
nonn,base
AUTHOR
Joseph C. Y. Wong, Oct 01 2022
STATUS
approved