A229186 Beginning position of n in the decimal expansion of the Champernowne constant.

11, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 1, 16, 18, 20, 22, 24, 26, 28, 30, 15, 34, 2, 38, 40, 42, 44, 46, 48, 50, 17, 37, 56, 3, 60, 62, 64, 66, 68, 70, 19, 39, 59, 78, 4, 82, 84, 86, 88, 90, 21, 41, 61, 81, 100, 5, 104, 106, 108, 110, 23

Offset: 0

Author

Eric W. Weisstein, Sep 15 2013

Keywords

• nonn
• base
• less

Comments

Ignoring the initial 0 to the left of the decimal point.

Same as A031297 but including the a(0) term.

Links

• Eric W. Weisstein, Table of n, a(n) for n = 0..999
• Eric Weisstein's World of Mathematics, Champernowne Constant Digits
• Eric Weisstein's World of Mathematics, Constant Digit Scanning

Crossrefs

Cf. A033307 (decimal expansion of the Champernowne constant).

Cf. A072290 (number of digits in the decimal expansion of the Champernowne constant that must be scanned to encounter all n-digit strings).

Cf. A031297 (same sequence but omitting the a(0) term).

Programs

Python

from itertools import count, islice
def agen():
    k, chap = 1, ".1"
    for n in count(0):
        target = str(n)
        while chap.find(target) == -1: k += 1; chap += str(k)
        yield chap.find(target)
print(list(islice(agen(), 70))) # Michael S. Branicky, Oct 06 2022