The OEIS is supported by the many generous donors to the OEIS Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A344636 Numbers k such that half the numbers from 0 to k inclusive contain the digit "1". 4
 1, 17, 23, 161, 269, 271, 1457, 3397, 3419, 3421, 13121, 44685, 118097, 674909, 674933, 1062881 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS Andrew Hilton (see Ref) refers to these as "half-one" numbers. REFERENCES Andrew Hilton, 101 Puzzles to Solve on your Microcomputer, 1984, HARRAP, page 57. LINKS Table of n, a(n) for n=1..16. EXAMPLE 1 is a term since among the numbers 0,1 exactly half contain a digit "1". 17 is a term since among the numbers 0,1,2,...,17 exactly half contain a digit "1". MATHEMATICA Select[2Range@2000, Length@Select[Range[0, #-1], MemberQ[IntegerDigits@#, 1]&]==#/2&]-1 (* Giorgos Kalogeropoulos, Jul 28 2021 *) PROG (Python 3) z=1 z_s = str(z) counts=0 for x in trange (0, 100000000000): x_s = str(x) if z_s in x_s: counts += 1 if counts / (x+1) == 0.5: print(x) CROSSREFS Cf. A344474, A344634, A343839, A011531, A016189. Sequence in context: A060252 A127924 A250640 * A108260 A062628 A127907 Adjacent sequences: A344633 A344634 A344635 * A344637 A344638 A344639 KEYWORD nonn,base,fini,full AUTHOR Glen Gilchrist, May 25 2021 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified September 7 13:22 EDT 2024. Contains 375730 sequences. (Running on oeis4.)