126000000domain: NAppears in sequencesa(n)=2a(n-1) but when sum of digits of 2a(n-1) is greater than 9 take a(n) = largest number < 2a(n-1) which has sum of digits = 9.at n=27A140134Total number of digits in palindromes with n digits.at n=13A240022Self-stuffable numbers (see the Comments section for definition).at n=26A322323