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

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A305213 a(n) is the smallest nonnegative integer whose first n binary digits coincide with its first n decimal digits. 4
 0, 10, 110, 10010, 10011, 110101, 10011000, 10011000, 110100011, 10010101000, 10010101001, 101111000101, 10010001101010, 10010001101010, 101101111110011, 1111110010100011, 10001110000111111, 101100111001011100, 1111011010110001101, 10001010110010101011, 101011110011100111110 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 LINKS Bert Dobbelaere, Table of n, a(n) for n = 1..150 EXAMPLE 10011 expressed in binary is 10011100011011_2. It is the smallest number for which the first 5 digits coincide, so a(5)=10011. PROG (Python) RDXHI=10 RDXLO=2 def solvematch(startHi, startLo, digleft, powHi, powLo): ....global RDXHI, RDXLO ....if digleft<=0: ........return startHi ....if powHi<0 or powLo<0: ........return None ....startd = 1 if startHi==0 else 0 ....for d in range(startd, RDXLO): ........bh=startHi + d * RDXHI**powHi ........bl=startLo + d * RDXLO**powLo ........if bh<(bl+RDXLO**powLo) and bl<(bh+RDXHI**powHi): ............res=solvematch(bh, bl, digleft-1, powHi-1, powLo-1) ............if res!=None: ................return res ....return None def A305213(n): ....if n<=1: ........return 0 # Special case: leading and only digit is 0 ....d_hi =n-1 ....sol=None ....while sol==None: ........d_lo=d_hi ........while(RDXLO**d_lo < 2* RDXHI**d_hi): ............res=solvematch(0, 0, n, d_hi, d_lo) ............if res!=None: ................sol = min(sol, res) if sol else res ............d_lo+=1 ........d_hi+=1 ....return sol CROSSREFS Not a subsequence of A181929 (consider 10010). Sequence in context: A337351 A146753 A297500 * A181929 A339713 A020767 Adjacent sequences: A305210 A305211 A305212 * A305214 A305215 A305216 KEYWORD nonn,base AUTHOR Bert Dobbelaere, May 27 2018 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 February 29 13:01 EST 2024. Contains 370425 sequences. (Running on oeis4.)