cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A004752 Binary expansion contains 010.

Original entry on oeis.org

10, 18, 20, 21, 26, 34, 36, 37, 40, 41, 42, 43, 50, 52, 53, 58, 66, 68, 69, 72, 73, 74, 75, 80, 81, 82, 83, 84, 85, 86, 87, 90, 98, 100, 101, 104, 105, 106, 107, 114, 116, 117, 122, 130, 132, 133, 136, 137, 138, 139, 144, 145, 146, 147, 148, 149, 150
Offset: 1

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Author

Keywords

Examples

			20 is in the sequence because, 20 = 10100_2 and '10100' has '010' as one of its substrings. - _Indranil Ghosh_, Feb 11 2017
		

Crossrefs

Programs

  • Mathematica
    Select[Range@ 150, Length@ SequencePosition[IntegerDigits[#, 2], {0, 1, 0}] > 0 &] (* Version 10.1, or *)
    Select[Range@ 150, MemberQ[Partition[IntegerDigits[#, 2], 3, 1], {0, 1, 0}] &] (* Michael De Vlieger, Feb 11 2017 *)
  • PARI
    is(n)=while(n>9, if(bitand(n, 7)==2, return(1)); n>>=1); 0 \\ Charles R Greathouse IV, Feb 11 2017
  • Python
    i=j=0
    while j<=100:
        if "010" in bin(i)[2:]:
            print(str(j)+" "+str(i))
            j+=1
        i+=1 # Indranil Ghosh, Feb 11 2017
    

Formula

a(n) ~ n. - Charles R Greathouse IV, Oct 23 2015

Extensions

Offset corrected by Charles R Greathouse IV, Feb 11 2017