A100470 n appears A055642(n) times (appearances equal number of decimal digits).

0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 30, 31, 31, 32, 32, 33, 33, 34, 34, 35, 35, 36, 36, 37, 37, 38, 38, 39, 39, 40, 40, 41

Offset

0,3

Comments

Lexicographically smallest nondecreasing left inverse to A117804: a(A117804(n)) = n. Gives the number to which belongs the digit A007376(n). - M. F. Hasler, Oct 23 2019

Links

Table of n, a(n) for n=0..72.

Prog

(Python)
from oeis_sequences.OEISsequences import bisection, bsearch
def A100470(n):
    def g(x): return x+(m:=len(str(x)))*(x+1)-10*(10**(m-1)-1)//9
    def f(x): return n+1+bsearch(g, x)
    return bisection(f, n+1, n+1)-n-(not n) # Chai Wah Wu, Mar 02 2026

Crossrefs

Cf. A055642, A030530 (n's appearances equal its number of bits).

Sequence in context: A285757 A136687 A086706 * A071604 A337769 A061069

Adjacent sequences: A100467 A100468 A100469 * A100471 A100472 A100473

Keyword

base,easy,nonn

Author

Rick L. Shepherd, Nov 21 2004

Status

approved