OFFSET
1,1
COMMENTS
The lower and upper asymptotic densities of this sequence are 1/18 and 10/27, respectively. - Amiram Eldar, Feb 27 2021
LINKS
Jeremy Gardiner, Table of n, a(n) for n = 1..1111
FORMULA
a(n) = n + (17*10^floor(log_10(9*n-8))-8)/9. - Alan Michael Gómez Calderón, May 15 2023
MATHEMATICA
Select[Range[300], IntegerDigits[#][[1]] == 2 &] (* T. D. Noe, Oct 02 2012 *)
PROG
(Python)
def agen():
yield 2
digits, adder = 1, 20
while True:
for i in range(10**digits): yield adder + i
digits, adder = digits+1, adder*10
g = agen()
print([next(g) for i in range(54)]) # Michael S. Branicky, Feb 20 2021
CROSSREFS
KEYWORD
nonn,base,easy
AUTHOR
Jeremy Gardiner, Oct 02 2012
STATUS
approved